# coding: utf-8
# pylint: disable = invalid-name, C0111, C0301
# pylint: disable = R0912, R0913, R0914, W0105, W0201, W0212
"""Wrapper for C API of LightGBM."""
from __future__ import absolute_import
import copy
import ctypes
import os
import warnings
from tempfile import NamedTemporaryFile
import numpy as np
import scipy.sparse
from .compat import (DataFrame, Series,
decode_string, string_type,
integer_types, numeric_types,
json, json_default_with_numpy,
range_, zip_)
from .libpath import find_lib_path
def _load_lib():
"""Load LightGBM library."""
lib_path = find_lib_path()
if len(lib_path) == 0:
return None
lib = ctypes.cdll.LoadLibrary(lib_path[0])
lib.LGBM_GetLastError.restype = ctypes.c_char_p
return lib
_LIB = _load_lib()
def _safe_call(ret):
"""Check the return value from C API call.
Parameters
----------
ret : int
The return value from C API calls.
"""
if ret != 0:
raise LightGBMError(decode_string(_LIB.LGBM_GetLastError()))
def is_numeric(obj):
"""Check whether object is a number or not, include numpy number, etc."""
try:
float(obj)
return True
except (TypeError, ValueError):
# TypeError: obj is not a string or a number
# ValueError: invalid literal
return False
def is_numpy_1d_array(data):
"""Check whether data is a 1-D numpy array."""
return isinstance(data, np.ndarray) and len(data.shape) == 1
def is_1d_list(data):
"""Check whether data is a 1-D list."""
return isinstance(data, list) and (not data or is_numeric(data[0]))
def list_to_1d_numpy(data, dtype=np.float32, name='list'):
"""Convert data to 1-D numpy array."""
if is_numpy_1d_array(data):
if data.dtype == dtype:
return data
else:
return data.astype(dtype=dtype, copy=False)
elif is_1d_list(data):
return np.array(data, dtype=dtype, copy=False)
elif isinstance(data, Series):
return data.values.astype(dtype)
else:
raise TypeError("Wrong type({0}) for {1}.\n"
"It should be list, numpy 1-D array or pandas Series".format(type(data).__name__, name))
def cfloat32_array_to_numpy(cptr, length):
"""Convert a ctypes float pointer array to a numpy array."""
if isinstance(cptr, ctypes.POINTER(ctypes.c_float)):
return np.fromiter(cptr, dtype=np.float32, count=length)
else:
raise RuntimeError('Expected float pointer')
def cfloat64_array_to_numpy(cptr, length):
"""Convert a ctypes double pointer array to a numpy array."""
if isinstance(cptr, ctypes.POINTER(ctypes.c_double)):
return np.fromiter(cptr, dtype=np.float64, count=length)
else:
raise RuntimeError('Expected double pointer')
def cint32_array_to_numpy(cptr, length):
"""Convert a ctypes int pointer array to a numpy array."""
if isinstance(cptr, ctypes.POINTER(ctypes.c_int32)):
return np.fromiter(cptr, dtype=np.int32, count=length)
else:
raise RuntimeError('Expected int pointer')
def c_str(string):
"""Convert a Python string to C string."""
return ctypes.c_char_p(string.encode('utf-8'))
def c_array(ctype, values):
"""Convert a Python array to C array."""
return (ctype * len(values))(*values)
def param_dict_to_str(data):
"""Convert Python dictionary to string, which is passed to C API."""
if data is None or not data:
return ""
pairs = []
for key, val in data.items():
if isinstance(val, (list, tuple, set)) or is_numpy_1d_array(val):
pairs.append(str(key) + '=' + ','.join(map(str, val)))
elif isinstance(val, string_type) or isinstance(val, numeric_types) or is_numeric(val):
pairs.append(str(key) + '=' + str(val))
elif val is not None:
raise TypeError('Unknown type of parameter:%s, got:%s'
% (key, type(val).__name__))
return ' '.join(pairs)
class _TempFile(object):
def __enter__(self):
with NamedTemporaryFile(prefix="lightgbm_tmp_", delete=True) as f:
self.name = f.name
return self
def __exit__(self, exc_type, exc_val, exc_tb):
if os.path.isfile(self.name):
os.remove(self.name)
def readlines(self):
with open(self.name, "r+") as f:
ret = f.readlines()
return ret
def writelines(self, lines):
with open(self.name, "w+") as f:
f.writelines(lines)
class LightGBMError(Exception):
"""Error thrown by LightGBM."""
pass
MAX_INT32 = (1 << 31) - 1
"""Macro definition of data type in C API of LightGBM"""
C_API_DTYPE_FLOAT32 = 0
C_API_DTYPE_FLOAT64 = 1
C_API_DTYPE_INT32 = 2
C_API_DTYPE_INT64 = 3
"""Matrix is row major in Python"""
C_API_IS_ROW_MAJOR = 1
"""Macro definition of prediction type in C API of LightGBM"""
C_API_PREDICT_NORMAL = 0
C_API_PREDICT_RAW_SCORE = 1
C_API_PREDICT_LEAF_INDEX = 2
C_API_PREDICT_CONTRIB = 3
"""Data type of data field"""
FIELD_TYPE_MAPPER = {"label": C_API_DTYPE_FLOAT32,
"weight": C_API_DTYPE_FLOAT32,
"init_score": C_API_DTYPE_FLOAT64,
"group": C_API_DTYPE_INT32}
PANDAS_DTYPE_MAPPER = {'int8': 'int', 'int16': 'int', 'int32': 'int',
'int64': 'int', 'uint8': 'int', 'uint16': 'int',
'uint32': 'int', 'uint64': 'int', 'bool': 'int',
'float16': 'float', 'float32': 'float', 'float64': 'float'}
def convert_from_sliced_object(data):
"""Fix the memory of multi-dimensional sliced object."""
if data.base is not None and isinstance(data, np.ndarray) and isinstance(data.base, np.ndarray):
if not data.flags.c_contiguous:
warnings.warn("Usage of np.ndarray subset (sliced data) is not recommended "
"due to it will double the peak memory cost in LightGBM.")
return np.copy(data)
return data
def c_float_array(data):
"""Get pointer of float numpy array / list."""
if is_1d_list(data):
data = np.array(data, copy=False)
if is_numpy_1d_array(data):
data = convert_from_sliced_object(data)
assert data.flags.c_contiguous
if data.dtype == np.float32:
ptr_data = data.ctypes.data_as(ctypes.POINTER(ctypes.c_float))
type_data = C_API_DTYPE_FLOAT32
elif data.dtype == np.float64:
ptr_data = data.ctypes.data_as(ctypes.POINTER(ctypes.c_double))
type_data = C_API_DTYPE_FLOAT64
else:
raise TypeError("Expected np.float32 or np.float64, met type({})"
.format(data.dtype))
else:
raise TypeError("Unknown type({})".format(type(data).__name__))
return (ptr_data, type_data, data) # return `data` to avoid the temporary copy is freed
def c_int_array(data):
"""Get pointer of int numpy array / list."""
if is_1d_list(data):
data = np.array(data, copy=False)
if is_numpy_1d_array(data):
data = convert_from_sliced_object(data)
assert data.flags.c_contiguous
if data.dtype == np.int32:
ptr_data = data.ctypes.data_as(ctypes.POINTER(ctypes.c_int32))
type_data = C_API_DTYPE_INT32
elif data.dtype == np.int64:
ptr_data = data.ctypes.data_as(ctypes.POINTER(ctypes.c_int64))
type_data = C_API_DTYPE_INT64
else:
raise TypeError("Expected np.int32 or np.int64, met type({})"
.format(data.dtype))
else:
raise TypeError("Unknown type({})".format(type(data).__name__))
return (ptr_data, type_data, data) # return `data` to avoid the temporary copy is freed
def _data_from_pandas(data, feature_name, categorical_feature, pandas_categorical):
if isinstance(data, DataFrame):
if len(data.shape) != 2 or data.shape[0] < 1:
raise ValueError('Input data must be 2 dimensional and non empty.')
if feature_name == 'auto' or feature_name is None:
data = data.rename(columns=str)
cat_cols = data.select_dtypes(include=['category']).columns
if pandas_categorical is None: # train dataset
pandas_categorical = [list(data[col].cat.categories) for col in cat_cols]
else:
if len(cat_cols) != len(pandas_categorical):
raise ValueError('train and valid dataset categorical_feature do not match.')
for col, category in zip_(cat_cols, pandas_categorical):
if list(data[col].cat.categories) != list(category):
data[col] = data[col].cat.set_categories(category)
if len(cat_cols): # cat_cols is pandas Index object
data = data.copy() # not alter origin DataFrame
data[cat_cols] = data[cat_cols].apply(lambda x: x.cat.codes).replace({-1: np.nan})
if categorical_feature is not None:
if feature_name is None:
feature_name = list(data.columns)
if categorical_feature == 'auto':
categorical_feature = list(cat_cols)
else:
categorical_feature = list(categorical_feature) + list(cat_cols)
if feature_name == 'auto':
feature_name = list(data.columns)
data_dtypes = data.dtypes
if not all(dtype.name in PANDAS_DTYPE_MAPPER for dtype in data_dtypes):
bad_fields = [data.columns[i] for i, dtype in
enumerate(data_dtypes) if dtype.name not in PANDAS_DTYPE_MAPPER]
msg = ("DataFrame.dtypes for data must be int, float or bool.\n"
"Did not expect the data types in fields ")
raise ValueError(msg + ', '.join(bad_fields))
data = data.values.astype('float')
else:
if feature_name == 'auto':
feature_name = None
if categorical_feature == 'auto':
categorical_feature = None
return data, feature_name, categorical_feature, pandas_categorical
def _label_from_pandas(label):
if isinstance(label, DataFrame):
if len(label.columns) > 1:
raise ValueError('DataFrame for label cannot have multiple columns')
label_dtypes = label.dtypes
if not all(dtype.name in PANDAS_DTYPE_MAPPER for dtype in label_dtypes):
raise ValueError('DataFrame.dtypes for label must be int, float or bool')
label = label.values.astype('float').flatten()
return label
def _dump_pandas_categorical(pandas_categorical, file_name=None):
pandas_str = ('\npandas_categorical:'
+ json.dumps(pandas_categorical, default=json_default_with_numpy)
+ '\n')
if file_name is not None:
with open(file_name, 'a') as f:
f.write(pandas_str)
return pandas_str
def _load_pandas_categorical(file_name=None, model_str=None):
if file_name is not None:
with open(file_name, 'r') as f:
lines = f.readlines()
last_line = lines[-1]
if last_line.strip() == "":
last_line = lines[-2]
if last_line.startswith('pandas_categorical:'):
return json.loads(last_line[len('pandas_categorical:'):])
elif model_str is not None:
lines = model_str.split('\n')
last_line = lines[-1]
if last_line.strip() == "":
last_line = lines[-2]
if last_line.startswith('pandas_categorical:'):
return json.loads(last_line[len('pandas_categorical:'):])
return None
class _InnerPredictor(object):
"""_InnerPredictor of LightGBM.
Not exposed to user.
Used only for prediction, usually used for continued training.
Note
----
Can be converted from Booster, but cannot be converted to Booster.
"""
def __init__(self, model_file=None, booster_handle=None, pred_parameter=None):
"""Initialize the _InnerPredictor.
Parameters
----------
model_file : string or None, optional (default=None)
Path to the model file.
booster_handle : object or None, optional (default=None)
Handle of Booster.
pred_parameter: dict or None, optional (default=None)
Other parameters for the prediciton.
"""
self.handle = ctypes.c_void_p()
self.__is_manage_handle = True
if model_file is not None:
"""Prediction task"""
out_num_iterations = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterCreateFromModelfile(
c_str(model_file),
ctypes.byref(out_num_iterations),
ctypes.byref(self.handle)))
out_num_class = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterGetNumClasses(
self.handle,
ctypes.byref(out_num_class)))
self.num_class = out_num_class.value
self.num_total_iteration = out_num_iterations.value
self.pandas_categorical = _load_pandas_categorical(file_name=model_file)
elif booster_handle is not None:
self.__is_manage_handle = False
self.handle = booster_handle
out_num_class = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterGetNumClasses(
self.handle,
ctypes.byref(out_num_class)))
self.num_class = out_num_class.value
out_num_iterations = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterGetCurrentIteration(
self.handle,
ctypes.byref(out_num_iterations)))
self.num_total_iteration = out_num_iterations.value
self.pandas_categorical = None
else:
raise TypeError('Need Model file or Booster handle to create a predictor')
pred_parameter = {} if pred_parameter is None else pred_parameter
self.pred_parameter = param_dict_to_str(pred_parameter)
def __del__(self):
try:
if self.__is_manage_handle:
_safe_call(_LIB.LGBM_BoosterFree(self.handle))
except AttributeError:
pass
def __getstate__(self):
this = self.__dict__.copy()
this.pop('handle', None)
return this
def predict(self, data, num_iteration=-1,
raw_score=False, pred_leaf=False, pred_contrib=False, data_has_header=False,
is_reshape=True):
"""Predict logic.
Parameters
----------
data : string, numpy array, pandas DataFrame or scipy.sparse
Data source for prediction.
When data type is string, it represents the path of txt file.
num_iteration : int, optional (default=-1)
Iteration used for prediction.
raw_score : bool, optional (default=False)
Whether to predict raw scores.
pred_leaf : bool, optional (default=False)
Whether to predict leaf index.
pred_contrib : bool, optional (default=False)
Whether to predict feature contributions.
data_has_header : bool, optional (default=False)
Whether data has header.
Used only for txt data.
is_reshape : bool, optional (default=True)
Whether to reshape to (nrow, ncol).
Returns
-------
result : numpy array
Prediction result.
"""
if isinstance(data, Dataset):
raise TypeError("Cannot use Dataset instance for prediction, please use raw data instead")
data = _data_from_pandas(data, None, None, self.pandas_categorical)[0]
predict_type = C_API_PREDICT_NORMAL
if raw_score:
predict_type = C_API_PREDICT_RAW_SCORE
if pred_leaf:
predict_type = C_API_PREDICT_LEAF_INDEX
if pred_contrib:
predict_type = C_API_PREDICT_CONTRIB
int_data_has_header = 1 if data_has_header else 0
if num_iteration > self.num_total_iteration:
num_iteration = self.num_total_iteration
if isinstance(data, string_type):
with _TempFile() as f:
_safe_call(_LIB.LGBM_BoosterPredictForFile(
self.handle,
c_str(data),
ctypes.c_int(int_data_has_header),
ctypes.c_int(predict_type),
ctypes.c_int(num_iteration),
c_str(self.pred_parameter),
c_str(f.name)))
lines = f.readlines()
nrow = len(lines)
preds = [float(token) for line in lines for token in line.split('\t')]
preds = np.array(preds, dtype=np.float64, copy=False)
elif isinstance(data, scipy.sparse.csr_matrix):
preds, nrow = self.__pred_for_csr(data, num_iteration, predict_type)
elif isinstance(data, scipy.sparse.csc_matrix):
preds, nrow = self.__pred_for_csc(data, num_iteration, predict_type)
elif isinstance(data, np.ndarray):
preds, nrow = self.__pred_for_np2d(data, num_iteration, predict_type)
elif isinstance(data, list):
try:
data = np.array(data)
except BaseException:
raise ValueError('Cannot convert data list to numpy array.')
preds, nrow = self.__pred_for_np2d(data, num_iteration, predict_type)
else:
try:
warnings.warn('Converting data to scipy sparse matrix.')
csr = scipy.sparse.csr_matrix(data)
except BaseException:
raise TypeError('Cannot predict data for type {}'.format(type(data).__name__))
preds, nrow = self.__pred_for_csr(csr, num_iteration, predict_type)
if pred_leaf:
preds = preds.astype(np.int32)
if is_reshape and preds.size != nrow:
if preds.size % nrow == 0:
preds = preds.reshape(nrow, -1)
else:
raise ValueError('Length of predict result (%d) cannot be divide nrow (%d)'
% (preds.size, nrow))
return preds
def __get_num_preds(self, num_iteration, nrow, predict_type):
"""Get size of prediction result."""
if nrow > MAX_INT32:
raise LightGBMError('LightGBM cannot perform prediction for data'
'with number of rows greater than MAX_INT32 (%d).\n'
'You can split your data into chunks'
'and then concatenate predictions for them' % MAX_INT32)
n_preds = ctypes.c_int64(0)
_safe_call(_LIB.LGBM_BoosterCalcNumPredict(
self.handle,
ctypes.c_int(nrow),
ctypes.c_int(predict_type),
ctypes.c_int(num_iteration),
ctypes.byref(n_preds)))
return n_preds.value
def __pred_for_np2d(self, mat, num_iteration, predict_type):
"""Predict for a 2-D numpy matrix."""
if len(mat.shape) != 2:
raise ValueError('Input numpy.ndarray or list must be 2 dimensional')
def inner_predict(mat, num_iteration, predict_type, preds=None):
if mat.dtype == np.float32 or mat.dtype == np.float64:
data = np.array(mat.reshape(mat.size), dtype=mat.dtype, copy=False)
else:
"""change non-float data to float data, need to copy"""
data = np.array(mat.reshape(mat.size), dtype=np.float32)
ptr_data, type_ptr_data, _ = c_float_array(data)
n_preds = self.__get_num_preds(num_iteration, mat.shape[0], predict_type)
if preds is None:
preds = np.zeros(n_preds, dtype=np.float64)
elif len(preds.shape) != 1 or len(preds) != n_preds:
raise ValueError("Wrong length of pre-allocated predict array")
out_num_preds = ctypes.c_int64(0)
_safe_call(_LIB.LGBM_BoosterPredictForMat(
self.handle,
ptr_data,
ctypes.c_int(type_ptr_data),
ctypes.c_int(mat.shape[0]),
ctypes.c_int(mat.shape[1]),
ctypes.c_int(C_API_IS_ROW_MAJOR),
ctypes.c_int(predict_type),
ctypes.c_int(num_iteration),
c_str(self.pred_parameter),
ctypes.byref(out_num_preds),
preds.ctypes.data_as(ctypes.POINTER(ctypes.c_double))))
if n_preds != out_num_preds.value:
raise ValueError("Wrong length for predict results")
return preds, mat.shape[0]
nrow = mat.shape[0]
if nrow > MAX_INT32:
sections = np.arange(start=MAX_INT32, stop=nrow, step=MAX_INT32)
# __get_num_preds() cannot work with nrow > MAX_INT32, so calculate overall number of predictions piecemeal
n_preds = [self.__get_num_preds(num_iteration, i, predict_type) for i in np.diff([0] + list(sections) + [nrow])]
n_preds_sections = np.array([0] + n_preds, dtype=np.intp).cumsum()
preds = np.zeros(sum(n_preds), dtype=np.float64)
for chunk, (start_idx_pred, end_idx_pred) in zip_(np.array_split(mat, sections),
zip_(n_preds_sections, n_preds_sections[1:])):
# avoid memory consumption by arrays concatenation operations
inner_predict(chunk, num_iteration, predict_type, preds[start_idx_pred:end_idx_pred])
return preds, nrow
else:
return inner_predict(mat, num_iteration, predict_type)
def __pred_for_csr(self, csr, num_iteration, predict_type):
"""Predict for a CSR data."""
def inner_predict(csr, num_iteration, predict_type, preds=None):
nrow = len(csr.indptr) - 1
n_preds = self.__get_num_preds(num_iteration, nrow, predict_type)
if preds is None:
preds = np.zeros(n_preds, dtype=np.float64)
elif len(preds.shape) != 1 or len(preds) != n_preds:
raise ValueError("Wrong length of pre-allocated predict array")
out_num_preds = ctypes.c_int64(0)
ptr_indptr, type_ptr_indptr, __ = c_int_array(csr.indptr)
ptr_data, type_ptr_data, _ = c_float_array(csr.data)
assert csr.shape[1] <= MAX_INT32
csr.indices = csr.indices.astype(np.int32, copy=False)
_safe_call(_LIB.LGBM_BoosterPredictForCSR(
self.handle,
ptr_indptr,
ctypes.c_int32(type_ptr_indptr),
csr.indices.ctypes.data_as(ctypes.POINTER(ctypes.c_int32)),
ptr_data,
ctypes.c_int(type_ptr_data),
ctypes.c_int64(len(csr.indptr)),
ctypes.c_int64(len(csr.data)),
ctypes.c_int64(csr.shape[1]),
ctypes.c_int(predict_type),
ctypes.c_int(num_iteration),
c_str(self.pred_parameter),
ctypes.byref(out_num_preds),
preds.ctypes.data_as(ctypes.POINTER(ctypes.c_double))))
if n_preds != out_num_preds.value:
raise ValueError("Wrong length for predict results")
return preds, nrow
nrow = len(csr.indptr) - 1
if nrow > MAX_INT32:
sections = [0] + list(np.arange(start=MAX_INT32, stop=nrow, step=MAX_INT32)) + [nrow]
# __get_num_preds() cannot work with nrow > MAX_INT32, so calculate overall number of predictions piecemeal
n_preds = [self.__get_num_preds(num_iteration, i, predict_type) for i in np.diff(sections)]
n_preds_sections = np.array([0] + n_preds, dtype=np.intp).cumsum()
preds = np.zeros(sum(n_preds), dtype=np.float64)
for (start_idx, end_idx), (start_idx_pred, end_idx_pred) in zip_(zip_(sections, sections[1:]),
zip_(n_preds_sections, n_preds_sections[1:])):
# avoid memory consumption by arrays concatenation operations
inner_predict(csr[start_idx:end_idx], num_iteration, predict_type, preds[start_idx_pred:end_idx_pred])
return preds, nrow
else:
return inner_predict(csr, num_iteration, predict_type)
def __pred_for_csc(self, csc, num_iteration, predict_type):
"""Predict for a CSC data."""
nrow = csc.shape[0]
if nrow > MAX_INT32:
return self.__pred_for_csr(csc.tocsr(), num_iteration, predict_type)
n_preds = self.__get_num_preds(num_iteration, nrow, predict_type)
preds = np.zeros(n_preds, dtype=np.float64)
out_num_preds = ctypes.c_int64(0)
ptr_indptr, type_ptr_indptr, __ = c_int_array(csc.indptr)
ptr_data, type_ptr_data, _ = c_float_array(csc.data)
assert csc.shape[0] <= MAX_INT32
csc.indices = csc.indices.astype(np.int32, copy=False)
_safe_call(_LIB.LGBM_BoosterPredictForCSC(
self.handle,
ptr_indptr,
ctypes.c_int32(type_ptr_indptr),
csc.indices.ctypes.data_as(ctypes.POINTER(ctypes.c_int32)),
ptr_data,
ctypes.c_int(type_ptr_data),
ctypes.c_int64(len(csc.indptr)),
ctypes.c_int64(len(csc.data)),
ctypes.c_int64(csc.shape[0]),
ctypes.c_int(predict_type),
ctypes.c_int(num_iteration),
c_str(self.pred_parameter),
ctypes.byref(out_num_preds),
preds.ctypes.data_as(ctypes.POINTER(ctypes.c_double))))
if n_preds != out_num_preds.value:
raise ValueError("Wrong length for predict results")
return preds, nrow
[docs]class Dataset(object):
"""Dataset in LightGBM."""
def __init__(self, data, label=None, reference=None,
weight=None, group=None, init_score=None, silent=False,
feature_name='auto', categorical_feature='auto', params=None,
free_raw_data=True):
"""Initialize Dataset.
Parameters
----------
data : string, numpy array, pandas DataFrame, scipy.sparse or list of numpy arrays
Data source of Dataset.
If string, it represents the path to txt file.
label : list, numpy 1-D array, pandas Series / one-column DataFrame or None, optional (default=None)
Label of the data.
reference : Dataset or None, optional (default=None)
If this is Dataset for validation, training data should be used as reference.
weight : list, numpy 1-D array, pandas Series or None, optional (default=None)
Weight for each instance.
group : list, numpy 1-D array, pandas Series or None, optional (default=None)
Group/query size for Dataset.
init_score : list, numpy 1-D array, pandas Series or None, optional (default=None)
Init score for Dataset.
silent : bool, optional (default=False)
Whether to print messages during construction.
feature_name : list of strings or 'auto', optional (default="auto")
Feature names.
If 'auto' and data is pandas DataFrame, data columns names are used.
categorical_feature : list of strings or int, or 'auto', optional (default="auto")
Categorical features.
If list of int, interpreted as indices.
If list of strings, interpreted as feature names (need to specify ``feature_name`` as well).
If 'auto' and data is pandas DataFrame, pandas categorical columns are used.
All values in categorical features should be less than int32 max value (2147483647).
Large values could be memory consuming. Consider using consecutive integers starting from zero.
All negative values in categorical features will be treated as missing values.
params : dict or None, optional (default=None)
Other parameters for Dataset.
free_raw_data : bool, optional (default=True)
If True, raw data is freed after constructing inner Dataset.
"""
self.handle = None
self.data = data
self.label = label
self.reference = reference
self.weight = weight
self.group = group
self.init_score = init_score
self.silent = silent
self.feature_name = feature_name
self.categorical_feature = categorical_feature
self.params = copy.deepcopy(params)
self.free_raw_data = free_raw_data
self.used_indices = None
self._predictor = None
self.pandas_categorical = None
self.params_back_up = None
def __del__(self):
try:
self._free_handle()
except AttributeError:
pass
def _free_handle(self):
if self.handle is not None:
_safe_call(_LIB.LGBM_DatasetFree(self.handle))
self.handle = None
return self
def _lazy_init(self, data, label=None, reference=None,
weight=None, group=None, init_score=None, predictor=None,
silent=False, feature_name='auto',
categorical_feature='auto', params=None):
if data is None:
self.handle = None
return self
if reference is not None:
self.pandas_categorical = reference.pandas_categorical
categorical_feature = reference.categorical_feature
data, feature_name, categorical_feature, self.pandas_categorical = _data_from_pandas(data,
feature_name,
categorical_feature,
self.pandas_categorical)
label = _label_from_pandas(label)
self.data_has_header = False
# process for args
params = {} if params is None else params
args_names = (getattr(self.__class__, '_lazy_init')
.__code__
.co_varnames[:getattr(self.__class__, '_lazy_init').__code__.co_argcount])
for key, _ in params.items():
if key in args_names:
warnings.warn('{0} keyword has been found in `params` and will be ignored.\n'
'Please use {0} argument of the Dataset constructor to pass this parameter.'
.format(key))
self.predictor = predictor
# user can set verbose with params, it has higher priority
if not any(verbose_alias in params for verbose_alias in ('verbose', 'verbosity')) and silent:
params["verbose"] = -1
# get categorical features
if categorical_feature is not None:
categorical_indices = set()
feature_dict = {}
if feature_name is not None:
feature_dict = {name: i for i, name in enumerate(feature_name)}
for name in categorical_feature:
if isinstance(name, string_type) and name in feature_dict:
categorical_indices.add(feature_dict[name])
elif isinstance(name, integer_types):
categorical_indices.add(name)
else:
raise TypeError("Wrong type({}) or unknown name({}) in categorical_feature"
.format(type(name).__name__, name))
if categorical_indices:
if "categorical_feature" in params or "categorical_column" in params:
warnings.warn('categorical_feature in param dict is overridden.')
params.pop("categorical_feature", None)
params.pop("categorical_column", None)
params['categorical_column'] = sorted(categorical_indices)
params_str = param_dict_to_str(params)
# process for reference dataset
ref_dataset = None
if isinstance(reference, Dataset):
ref_dataset = reference.construct().handle
elif reference is not None:
raise TypeError('Reference dataset should be None or dataset instance')
# start construct data
if isinstance(data, string_type):
# check data has header or not
if str(params.get("has_header", "")).lower() == "true" \
or str(params.get("header", "")).lower() == "true":
self.data_has_header = True
self.handle = ctypes.c_void_p()
_safe_call(_LIB.LGBM_DatasetCreateFromFile(
c_str(data),
c_str(params_str),
ref_dataset,
ctypes.byref(self.handle)))
elif isinstance(data, scipy.sparse.csr_matrix):
self.__init_from_csr(data, params_str, ref_dataset)
elif isinstance(data, scipy.sparse.csc_matrix):
self.__init_from_csc(data, params_str, ref_dataset)
elif isinstance(data, np.ndarray):
self.__init_from_np2d(data, params_str, ref_dataset)
elif isinstance(data, list) and len(data) > 0 and all(isinstance(x, np.ndarray) for x in data):
self.__init_from_list_np2d(data, params_str, ref_dataset)
else:
try:
csr = scipy.sparse.csr_matrix(data)
self.__init_from_csr(csr, params_str, ref_dataset)
except BaseException:
raise TypeError('Cannot initialize Dataset from {}'.format(type(data).__name__))
if label is not None:
self.set_label(label)
if self.get_label() is None:
raise ValueError("Label should not be None")
if weight is not None:
self.set_weight(weight)
if group is not None:
self.set_group(group)
# load init score
if init_score is not None:
self.set_init_score(init_score)
if self.predictor is not None:
warnings.warn("The prediction of init_model will be overridden by init_score.")
elif isinstance(self.predictor, _InnerPredictor):
init_score = self.predictor.predict(data,
raw_score=True,
data_has_header=self.data_has_header,
is_reshape=False)
if self.predictor.num_class > 1:
# need re group init score
new_init_score = np.zeros(init_score.size, dtype=np.float32)
num_data = self.num_data()
for i in range_(num_data):
for j in range_(self.predictor.num_class):
new_init_score[j * num_data + i] = init_score[i * self.predictor.num_class + j]
init_score = new_init_score
self.set_init_score(init_score)
elif self.predictor is not None:
raise TypeError('wrong predictor type {}'.format(type(self.predictor).__name__))
# set feature names
return self.set_feature_name(feature_name)
def __init_from_np2d(self, mat, params_str, ref_dataset):
"""Initialize data from a 2-D numpy matrix."""
if len(mat.shape) != 2:
raise ValueError('Input numpy.ndarray must be 2 dimensional')
self.handle = ctypes.c_void_p()
if mat.dtype == np.float32 or mat.dtype == np.float64:
data = np.array(mat.reshape(mat.size), dtype=mat.dtype, copy=False)
else:
# change non-float data to float data, need to copy
data = np.array(mat.reshape(mat.size), dtype=np.float32)
ptr_data, type_ptr_data, _ = c_float_array(data)
_safe_call(_LIB.LGBM_DatasetCreateFromMat(
ptr_data,
ctypes.c_int(type_ptr_data),
ctypes.c_int(mat.shape[0]),
ctypes.c_int(mat.shape[1]),
ctypes.c_int(C_API_IS_ROW_MAJOR),
c_str(params_str),
ref_dataset,
ctypes.byref(self.handle)))
return self
def __init_from_list_np2d(self, mats, params_str, ref_dataset):
"""Initialize data from a list of 2-D numpy matrices."""
ncol = mats[0].shape[1]
nrow = np.zeros((len(mats),), np.int32)
if mats[0].dtype == np.float64:
ptr_data = (ctypes.POINTER(ctypes.c_double) * len(mats))()
else:
ptr_data = (ctypes.POINTER(ctypes.c_float) * len(mats))()
holders = []
type_ptr_data = None
for i, mat in enumerate(mats):
if len(mat.shape) != 2:
raise ValueError('Input numpy.ndarray must be 2 dimensional')
if mat.shape[1] != ncol:
raise ValueError('Input arrays must have same number of columns')
nrow[i] = mat.shape[0]
if mat.dtype == np.float32 or mat.dtype == np.float64:
mats[i] = np.array(mat.reshape(mat.size), dtype=mat.dtype, copy=False)
else:
# change non-float data to float data, need to copy
mats[i] = np.array(mat.reshape(mat.size), dtype=np.float32)
chunk_ptr_data, chunk_type_ptr_data, holder = c_float_array(mats[i])
if type_ptr_data is not None and chunk_type_ptr_data != type_ptr_data:
raise ValueError('Input chunks must have same type')
ptr_data[i] = chunk_ptr_data
type_ptr_data = chunk_type_ptr_data
holders.append(holder)
self.handle = ctypes.c_void_p()
_safe_call(_LIB.LGBM_DatasetCreateFromMats(
ctypes.c_int(len(mats)),
ctypes.cast(ptr_data, ctypes.POINTER(ctypes.POINTER(ctypes.c_double))),
ctypes.c_int(type_ptr_data),
nrow.ctypes.data_as(ctypes.POINTER(ctypes.c_int32)),
ctypes.c_int(ncol),
ctypes.c_int(C_API_IS_ROW_MAJOR),
c_str(params_str),
ref_dataset,
ctypes.byref(self.handle)))
return self
def __init_from_csr(self, csr, params_str, ref_dataset):
"""Initialize data from a CSR matrix."""
if len(csr.indices) != len(csr.data):
raise ValueError('Length mismatch: {} vs {}'.format(len(csr.indices), len(csr.data)))
self.handle = ctypes.c_void_p()
ptr_indptr, type_ptr_indptr, __ = c_int_array(csr.indptr)
ptr_data, type_ptr_data, _ = c_float_array(csr.data)
assert csr.shape[1] <= MAX_INT32
csr.indices = csr.indices.astype(np.int32, copy=False)
_safe_call(_LIB.LGBM_DatasetCreateFromCSR(
ptr_indptr,
ctypes.c_int(type_ptr_indptr),
csr.indices.ctypes.data_as(ctypes.POINTER(ctypes.c_int32)),
ptr_data,
ctypes.c_int(type_ptr_data),
ctypes.c_int64(len(csr.indptr)),
ctypes.c_int64(len(csr.data)),
ctypes.c_int64(csr.shape[1]),
c_str(params_str),
ref_dataset,
ctypes.byref(self.handle)))
return self
def __init_from_csc(self, csc, params_str, ref_dataset):
"""Initialize data from a CSC matrix."""
if len(csc.indices) != len(csc.data):
raise ValueError('Length mismatch: {} vs {}'.format(len(csc.indices), len(csc.data)))
self.handle = ctypes.c_void_p()
ptr_indptr, type_ptr_indptr, __ = c_int_array(csc.indptr)
ptr_data, type_ptr_data, _ = c_float_array(csc.data)
assert csc.shape[0] <= MAX_INT32
csc.indices = csc.indices.astype(np.int32, copy=False)
_safe_call(_LIB.LGBM_DatasetCreateFromCSC(
ptr_indptr,
ctypes.c_int(type_ptr_indptr),
csc.indices.ctypes.data_as(ctypes.POINTER(ctypes.c_int32)),
ptr_data,
ctypes.c_int(type_ptr_data),
ctypes.c_int64(len(csc.indptr)),
ctypes.c_int64(len(csc.data)),
ctypes.c_int64(csc.shape[0]),
c_str(params_str),
ref_dataset,
ctypes.byref(self.handle)))
return self
[docs] def construct(self):
"""Lazy init.
Returns
-------
self : Dataset
Constructed Dataset object.
"""
if self.handle is None:
if self.reference is not None:
if self.used_indices is None:
# create valid
self._lazy_init(self.data, label=self.label, reference=self.reference,
weight=self.weight, group=self.group,
init_score=self.init_score, predictor=self._predictor,
silent=self.silent, feature_name=self.feature_name, params=self.params)
else:
# construct subset
used_indices = list_to_1d_numpy(self.used_indices, np.int32, name='used_indices')
assert used_indices.flags.c_contiguous
if self.reference.group is not None:
group_info = np.array(self.reference.group).astype(int)
_, self.group = np.unique(np.repeat(range_(len(group_info)), repeats=group_info)[self.used_indices],
return_counts=True)
self.handle = ctypes.c_void_p()
params_str = param_dict_to_str(self.params)
_safe_call(_LIB.LGBM_DatasetGetSubset(
self.reference.construct().handle,
used_indices.ctypes.data_as(ctypes.POINTER(ctypes.c_int32)),
ctypes.c_int(used_indices.shape[0]),
c_str(params_str),
ctypes.byref(self.handle)))
if self.group is not None:
self.set_group(self.group)
if self.get_label() is None:
raise ValueError("Label should not be None.")
else:
# create train
self._lazy_init(self.data, label=self.label,
weight=self.weight, group=self.group,
init_score=self.init_score, predictor=self._predictor,
silent=self.silent, feature_name=self.feature_name,
categorical_feature=self.categorical_feature, params=self.params)
if self.free_raw_data:
self.data = None
return self
[docs] def create_valid(self, data, label=None, weight=None, group=None,
init_score=None, silent=False, params=None):
"""Create validation data align with current Dataset.
Parameters
----------
data : string, numpy array, pandas DataFrame, scipy.sparse or list of numpy arrays
Data source of Dataset.
If string, it represents the path to txt file.
label : list, numpy 1-D array, pandas Series / one-column DataFrame or None, optional (default=None)
Label of the data.
weight : list, numpy 1-D array, pandas Series or None, optional (default=None)
Weight for each instance.
group : list, numpy 1-D array, pandas Series or None, optional (default=None)
Group/query size for Dataset.
init_score : list, numpy 1-D array, pandas Series or None, optional (default=None)
Init score for Dataset.
silent : bool, optional (default=False)
Whether to print messages during construction.
params : dict or None, optional (default=None)
Other parameters for validation Dataset.
Returns
-------
valid : Dataset
Validation Dataset with reference to self.
"""
ret = Dataset(data, label=label, reference=self,
weight=weight, group=group, init_score=init_score,
silent=silent, params=params, free_raw_data=self.free_raw_data)
ret._predictor = self._predictor
ret.pandas_categorical = self.pandas_categorical
return ret
[docs] def subset(self, used_indices, params=None):
"""Get subset of current Dataset.
Parameters
----------
used_indices : list of int
Indices used to create the subset.
params : dict or None, optional (default=None)
These parameters will be passed to Dataset constructor.
Returns
-------
subset : Dataset
Subset of the current Dataset.
"""
if params is None:
params = self.params
ret = Dataset(None, reference=self, feature_name=self.feature_name,
categorical_feature=self.categorical_feature, params=params)
ret._predictor = self._predictor
ret.pandas_categorical = self.pandas_categorical
ret.used_indices = used_indices
return ret
[docs] def save_binary(self, filename):
"""Save Dataset to a binary file.
Parameters
----------
filename : string
Name of the output file.
Returns
-------
self : Dataset
Returns self.
"""
_safe_call(_LIB.LGBM_DatasetSaveBinary(
self.construct().handle,
c_str(filename)))
return self
def _update_params(self, params):
if not self.params:
self.params = params
else:
self.params_back_up = copy.deepcopy(self.params)
self.params.update(params)
return self
def _reverse_update_params(self):
self.params = copy.deepcopy(self.params_back_up)
self.params_back_up = None
return self
[docs] def set_field(self, field_name, data):
"""Set property into the Dataset.
Parameters
----------
field_name : string
The field name of the information.
data : list, numpy 1-D array, pandas Series or None
The array of data to be set.
Returns
-------
self : Dataset
Dataset with set property.
"""
if self.handle is None:
raise Exception("Cannot set %s before construct dataset" % field_name)
if data is None:
# set to None
_safe_call(_LIB.LGBM_DatasetSetField(
self.handle,
c_str(field_name),
None,
ctypes.c_int(0),
ctypes.c_int(FIELD_TYPE_MAPPER[field_name])))
return self
dtype = np.float32
if field_name == 'group':
dtype = np.int32
elif field_name == 'init_score':
dtype = np.float64
data = list_to_1d_numpy(data, dtype, name=field_name)
if data.dtype == np.float32 or data.dtype == np.float64:
ptr_data, type_data, _ = c_float_array(data)
elif data.dtype == np.int32:
ptr_data, type_data, _ = c_int_array(data)
else:
raise TypeError("Excepted np.float32/64 or np.int32, meet type({})".format(data.dtype))
if type_data != FIELD_TYPE_MAPPER[field_name]:
raise TypeError("Input type error for set_field")
_safe_call(_LIB.LGBM_DatasetSetField(
self.handle,
c_str(field_name),
ptr_data,
ctypes.c_int(len(data)),
ctypes.c_int(type_data)))
return self
[docs] def get_field(self, field_name):
"""Get property from the Dataset.
Parameters
----------
field_name : string
The field name of the information.
Returns
-------
info : numpy array
A numpy array with information from the Dataset.
"""
if self.handle is None:
raise Exception("Cannot get %s before construct Dataset" % field_name)
tmp_out_len = ctypes.c_int()
out_type = ctypes.c_int()
ret = ctypes.POINTER(ctypes.c_void_p)()
_safe_call(_LIB.LGBM_DatasetGetField(
self.handle,
c_str(field_name),
ctypes.byref(tmp_out_len),
ctypes.byref(ret),
ctypes.byref(out_type)))
if out_type.value != FIELD_TYPE_MAPPER[field_name]:
raise TypeError("Return type error for get_field")
if tmp_out_len.value == 0:
return None
if out_type.value == C_API_DTYPE_INT32:
return cint32_array_to_numpy(ctypes.cast(ret, ctypes.POINTER(ctypes.c_int32)), tmp_out_len.value)
elif out_type.value == C_API_DTYPE_FLOAT32:
return cfloat32_array_to_numpy(ctypes.cast(ret, ctypes.POINTER(ctypes.c_float)), tmp_out_len.value)
elif out_type.value == C_API_DTYPE_FLOAT64:
return cfloat64_array_to_numpy(ctypes.cast(ret, ctypes.POINTER(ctypes.c_double)), tmp_out_len.value)
else:
raise TypeError("Unknown type")
[docs] def set_categorical_feature(self, categorical_feature):
"""Set categorical features.
Parameters
----------
categorical_feature : list of int or strings
Names or indices of categorical features.
Returns
-------
self : Dataset
Dataset with set categorical features.
"""
if self.categorical_feature == categorical_feature:
return self
if self.data is not None:
if self.categorical_feature is None:
self.categorical_feature = categorical_feature
return self._free_handle()
elif categorical_feature == 'auto':
warnings.warn('Using categorical_feature in Dataset.')
return self
else:
warnings.warn('categorical_feature in Dataset is overridden.\n'
'New categorical_feature is {}'.format(sorted(list(categorical_feature))))
self.categorical_feature = categorical_feature
return self._free_handle()
else:
raise LightGBMError("Cannot set categorical feature after freed raw data, "
"set free_raw_data=False when construct Dataset to avoid this.")
def _set_predictor(self, predictor):
"""Set predictor for continued training.
It is not recommended for user to call this function.
Please use init_model argument in engine.train() or engine.cv() instead.
"""
if predictor is self._predictor:
return self
if self.data is not None:
self._predictor = predictor
return self._free_handle()
else:
raise LightGBMError("Cannot set predictor after freed raw data, "
"set free_raw_data=False when construct Dataset to avoid this.")
[docs] def set_reference(self, reference):
"""Set reference Dataset.
Parameters
----------
reference : Dataset
Reference that is used as a template to construct the current Dataset.
Returns
-------
self : Dataset
Dataset with set reference.
"""
self.set_categorical_feature(reference.categorical_feature) \
.set_feature_name(reference.feature_name) \
._set_predictor(reference._predictor)
# we're done if self and reference share a common upstrem reference
if self.get_ref_chain().intersection(reference.get_ref_chain()):
return self
if self.data is not None:
self.reference = reference
return self._free_handle()
else:
raise LightGBMError("Cannot set reference after freed raw data, "
"set free_raw_data=False when construct Dataset to avoid this.")
[docs] def set_feature_name(self, feature_name):
"""Set feature name.
Parameters
----------
feature_name : list of strings
Feature names.
Returns
-------
self : Dataset
Dataset with set feature name.
"""
if feature_name != 'auto':
self.feature_name = feature_name
if self.handle is not None and feature_name is not None and feature_name != 'auto':
if len(feature_name) != self.num_feature():
raise ValueError("Length of feature_name({}) and num_feature({}) don't match"
.format(len(feature_name), self.num_feature()))
c_feature_name = [c_str(name) for name in feature_name]
_safe_call(_LIB.LGBM_DatasetSetFeatureNames(
self.handle,
c_array(ctypes.c_char_p, c_feature_name),
ctypes.c_int(len(feature_name))))
return self
[docs] def set_label(self, label):
"""Set label of Dataset.
Parameters
----------
label : list, numpy 1-D array, pandas Series / one-column DataFrame or None
The label information to be set into Dataset.
Returns
-------
self : Dataset
Dataset with set label.
"""
self.label = label
if self.handle is not None:
label = list_to_1d_numpy(_label_from_pandas(label), name='label')
self.set_field('label', label)
return self
[docs] def set_weight(self, weight):
"""Set weight of each instance.
Parameters
----------
weight : list, numpy 1-D array, pandas Series or None
Weight to be set for each data point.
Returns
-------
self : Dataset
Dataset with set weight.
"""
if weight is not None and np.all(weight == 1):
weight = None
self.weight = weight
if self.handle is not None and weight is not None:
weight = list_to_1d_numpy(weight, name='weight')
self.set_field('weight', weight)
return self
[docs] def set_init_score(self, init_score):
"""Set init score of Booster to start from.
Parameters
----------
init_score : list, numpy 1-D array, pandas Series or None
Init score for Booster.
Returns
-------
self : Dataset
Dataset with set init score.
"""
self.init_score = init_score
if self.handle is not None and init_score is not None:
init_score = list_to_1d_numpy(init_score, np.float64, name='init_score')
self.set_field('init_score', init_score)
return self
[docs] def set_group(self, group):
"""Set group size of Dataset (used for ranking).
Parameters
----------
group : list, numpy 1-D array, pandas Series or None
Group size of each group.
Returns
-------
self : Dataset
Dataset with set group.
"""
self.group = group
if self.handle is not None and group is not None:
group = list_to_1d_numpy(group, np.int32, name='group')
self.set_field('group', group)
return self
[docs] def get_label(self):
"""Get the label of the Dataset.
Returns
-------
label : numpy array or None
The label information from the Dataset.
"""
if self.label is None:
self.label = self.get_field('label')
return self.label
[docs] def get_weight(self):
"""Get the weight of the Dataset.
Returns
-------
weight : numpy array or None
Weight for each data point from the Dataset.
"""
if self.weight is None:
self.weight = self.get_field('weight')
return self.weight
[docs] def get_init_score(self):
"""Get the initial score of the Dataset.
Returns
-------
init_score : numpy array or None
Init score of Booster.
"""
if self.init_score is None:
self.init_score = self.get_field('init_score')
return self.init_score
[docs] def get_group(self):
"""Get the group of the Dataset.
Returns
-------
group : numpy array or None
Group size of each group.
"""
if self.group is None:
self.group = self.get_field('group')
if self.group is not None:
# group data from LightGBM is boundaries data, need to convert to group size
self.group = np.diff(self.group)
return self.group
[docs] def num_data(self):
"""Get the number of rows in the Dataset.
Returns
-------
number_of_rows : int
The number of rows in the Dataset.
"""
if self.handle is not None:
ret = ctypes.c_int()
_safe_call(_LIB.LGBM_DatasetGetNumData(self.handle,
ctypes.byref(ret)))
return ret.value
else:
raise LightGBMError("Cannot get num_data before construct dataset")
[docs] def num_feature(self):
"""Get the number of columns (features) in the Dataset.
Returns
-------
number_of_columns : int
The number of columns (features) in the Dataset.
"""
if self.handle is not None:
ret = ctypes.c_int()
_safe_call(_LIB.LGBM_DatasetGetNumFeature(self.handle,
ctypes.byref(ret)))
return ret.value
else:
raise LightGBMError("Cannot get num_feature before construct dataset")
[docs] def get_ref_chain(self, ref_limit=100):
"""Get a chain of Dataset objects.
Starts with r, then goes to r.reference (if exists),
then to r.reference.reference, etc.
until we hit ``ref_limit`` or a reference loop.
Parameters
----------
ref_limit : int, optional (default=100)
The limit number of references.
Returns
-------
ref_chain : set of Dataset
Chain of references of the Datasets.
"""
head = self
ref_chain = set()
while len(ref_chain) < ref_limit:
if isinstance(head, Dataset):
ref_chain.add(head)
if (head.reference is not None) and (head.reference not in ref_chain):
head = head.reference
else:
break
else:
break
return ref_chain
[docs]class Booster(object):
"""Booster in LightGBM."""
def __init__(self, params=None, train_set=None, model_file=None, silent=False):
"""Initialize the Booster.
Parameters
----------
params : dict or None, optional (default=None)
Parameters for Booster.
train_set : Dataset or None, optional (default=None)
Training dataset.
model_file : string or None, optional (default=None)
Path to the model file.
silent : bool, optional (default=False)
Whether to print messages during construction.
"""
self.handle = None
self.network = False
self.__need_reload_eval_info = True
self.__train_data_name = "training"
self.__attr = {}
self.__set_objective_to_none = False
self.best_iteration = -1
self.best_score = {}
params = {} if params is None else copy.deepcopy(params)
# user can set verbose with params, it has higher priority
if not any(verbose_alias in params for verbose_alias in ('verbose', 'verbosity')) and silent:
params["verbose"] = -1
if train_set is not None:
# Training task
if not isinstance(train_set, Dataset):
raise TypeError('Training data should be Dataset instance, met {}'
.format(type(train_set).__name__))
params_str = param_dict_to_str(params)
# set network if necessary
for alias in ["machines", "workers", "nodes"]:
if alias in params:
machines = params[alias]
if isinstance(machines, string_type):
num_machines = len(machines.split(','))
elif isinstance(machines, (list, set)):
num_machines = len(machines)
machines = ','.join(machines)
else:
raise ValueError("Invalid machines in params.")
self.set_network(machines,
local_listen_port=params.get("local_listen_port", 12400),
listen_time_out=params.get("listen_time_out", 120),
num_machines=params.get("num_machines", num_machines))
break
# construct booster object
self.handle = ctypes.c_void_p()
_safe_call(_LIB.LGBM_BoosterCreate(
train_set.construct().handle,
c_str(params_str),
ctypes.byref(self.handle)))
# save reference to data
self.train_set = train_set
self.valid_sets = []
self.name_valid_sets = []
self.__num_dataset = 1
self.__init_predictor = train_set._predictor
if self.__init_predictor is not None:
_safe_call(_LIB.LGBM_BoosterMerge(
self.handle,
self.__init_predictor.handle))
out_num_class = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterGetNumClasses(
self.handle,
ctypes.byref(out_num_class)))
self.__num_class = out_num_class.value
# buffer for inner predict
self.__inner_predict_buffer = [None]
self.__is_predicted_cur_iter = [False]
self.__get_eval_info()
self.pandas_categorical = train_set.pandas_categorical
elif model_file is not None:
# Prediction task
out_num_iterations = ctypes.c_int(0)
self.handle = ctypes.c_void_p()
_safe_call(_LIB.LGBM_BoosterCreateFromModelfile(
c_str(model_file),
ctypes.byref(out_num_iterations),
ctypes.byref(self.handle)))
out_num_class = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterGetNumClasses(
self.handle,
ctypes.byref(out_num_class)))
self.__num_class = out_num_class.value
self.pandas_categorical = _load_pandas_categorical(file_name=model_file)
elif 'model_str' in params:
self.model_from_string(params['model_str'], False)
else:
raise TypeError('Need at least one training dataset or model file to create booster instance')
self.params = params
def __del__(self):
try:
if self.network:
self.free_network()
except AttributeError:
pass
try:
if self.handle is not None:
_safe_call(_LIB.LGBM_BoosterFree(self.handle))
except AttributeError:
pass
def __copy__(self):
return self.__deepcopy__(None)
def __deepcopy__(self, _):
model_str = self.model_to_string(num_iteration=-1)
booster = Booster({'model_str': model_str})
return booster
def __getstate__(self):
this = self.__dict__.copy()
handle = this['handle']
this.pop('train_set', None)
this.pop('valid_sets', None)
if handle is not None:
this["handle"] = self.model_to_string(num_iteration=-1)
return this
def __setstate__(self, state):
model_str = state.get('handle', None)
if model_str is not None:
handle = ctypes.c_void_p()
out_num_iterations = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterLoadModelFromString(
c_str(model_str),
ctypes.byref(out_num_iterations),
ctypes.byref(handle)))
state['handle'] = handle
self.__dict__.update(state)
[docs] def free_dataset(self):
"""Free Booster's Datasets.
Returns
-------
self : Booster
Booster without Datasets.
"""
self.__dict__.pop('train_set', None)
self.__dict__.pop('valid_sets', None)
self.__num_dataset = 0
return self
def _free_buffer(self):
self.__inner_predict_buffer = []
self.__is_predicted_cur_iter = []
return self
[docs] def set_network(self, machines, local_listen_port=12400,
listen_time_out=120, num_machines=1):
"""Set the network configuration.
Parameters
----------
machines : list, set or string
Names of machines.
local_listen_port : int, optional (default=12400)
TCP listen port for local machines.
listen_time_out : int, optional (default=120)
Socket time-out in minutes.
num_machines : int, optional (default=1)
The number of machines for parallel learning application.
Returns
-------
self : Booster
Booster with set network.
"""
_safe_call(_LIB.LGBM_NetworkInit(c_str(machines),
ctypes.c_int(local_listen_port),
ctypes.c_int(listen_time_out),
ctypes.c_int(num_machines)))
self.network = True
return self
[docs] def free_network(self):
"""Free Booster's network.
Returns
-------
self : Booster
Booster with freed network.
"""
_safe_call(_LIB.LGBM_NetworkFree())
self.network = False
return self
[docs] def set_train_data_name(self, name):
"""Set the name to the training Dataset.
Parameters
----------
name : string
Name for the training Dataset.
Returns
-------
self : Booster
Booster with set training Dataset name.
"""
self.__train_data_name = name
return self
[docs] def add_valid(self, data, name):
"""Add validation data.
Parameters
----------
data : Dataset
Validation data.
name : string
Name of validation data.
Returns
-------
self : Booster
Booster with set validation data.
"""
if not isinstance(data, Dataset):
raise TypeError('Validation data should be Dataset instance, met {}'
.format(type(data).__name__))
if data._predictor is not self.__init_predictor:
raise LightGBMError("Add validation data failed, "
"you should use same predictor for these data")
_safe_call(_LIB.LGBM_BoosterAddValidData(
self.handle,
data.construct().handle))
self.valid_sets.append(data)
self.name_valid_sets.append(name)
self.__num_dataset += 1
self.__inner_predict_buffer.append(None)
self.__is_predicted_cur_iter.append(False)
return self
[docs] def reset_parameter(self, params):
"""Reset parameters of Booster.
Parameters
----------
params : dict
New parameters for Booster.
Returns
-------
self : Booster
Booster with new parameters.
"""
if any(metric_alias in params for metric_alias in ('metric', 'metrics', 'metric_types')):
self.__need_reload_eval_info = True
params_str = param_dict_to_str(params)
if params_str:
_safe_call(_LIB.LGBM_BoosterResetParameter(
self.handle,
c_str(params_str)))
self.params.update(params)
return self
[docs] def update(self, train_set=None, fobj=None):
"""Update Booster for one iteration.
Parameters
----------
train_set : Dataset or None, optional (default=None)
Training data.
If None, last training data is used.
fobj : callable or None, optional (default=None)
Customized objective function.
For multi-class task, the score is group by class_id first, then group by row_id.
If you want to get i-th row score in j-th class, the access way is score[j * num_data + i]
and you should group grad and hess in this way as well.
Returns
-------
is_finished : bool
Whether the update was successfully finished.
"""
# need reset training data
if train_set is not None and train_set is not self.train_set:
if not isinstance(train_set, Dataset):
raise TypeError('Training data should be Dataset instance, met {}'
.format(type(train_set).__name__))
if train_set._predictor is not self.__init_predictor:
raise LightGBMError("Replace training data failed, "
"you should use same predictor for these data")
self.train_set = train_set
_safe_call(_LIB.LGBM_BoosterResetTrainingData(
self.handle,
self.train_set.construct().handle))
self.__inner_predict_buffer[0] = None
is_finished = ctypes.c_int(0)
if fobj is None:
if self.__set_objective_to_none:
raise LightGBMError('Cannot update due to null objective function.')
_safe_call(_LIB.LGBM_BoosterUpdateOneIter(
self.handle,
ctypes.byref(is_finished)))
self.__is_predicted_cur_iter = [False for _ in range_(self.__num_dataset)]
return is_finished.value == 1
else:
if not self.__set_objective_to_none:
self.reset_parameter({"objective": "none"}).__set_objective_to_none = True
grad, hess = fobj(self.__inner_predict(0), self.train_set)
return self.__boost(grad, hess)
def __boost(self, grad, hess):
"""Boost Booster for one iteration with customized gradient statistics.
Note
----
For multi-class task, the score is group by class_id first, then group by row_id.
If you want to get i-th row score in j-th class, the access way is score[j * num_data + i]
and you should group grad and hess in this way as well.
Parameters
----------
grad : 1-D numpy array or 1-D list
The first order derivative (gradient).
hess : 1-D numpy array or 1-D list
The second order derivative (Hessian).
Returns
-------
is_finished : bool
Whether the boost was successfully finished.
"""
grad = list_to_1d_numpy(grad, name='gradient')
hess = list_to_1d_numpy(hess, name='hessian')
assert grad.flags.c_contiguous
assert hess.flags.c_contiguous
if len(grad) != len(hess):
raise ValueError("Lengths of gradient({}) and hessian({}) don't match"
.format(len(grad), len(hess)))
is_finished = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterUpdateOneIterCustom(
self.handle,
grad.ctypes.data_as(ctypes.POINTER(ctypes.c_float)),
hess.ctypes.data_as(ctypes.POINTER(ctypes.c_float)),
ctypes.byref(is_finished)))
self.__is_predicted_cur_iter = [False for _ in range_(self.__num_dataset)]
return is_finished.value == 1
[docs] def rollback_one_iter(self):
"""Rollback one iteration.
Returns
-------
self : Booster
Booster with rolled back one iteration.
"""
_safe_call(_LIB.LGBM_BoosterRollbackOneIter(
self.handle))
self.__is_predicted_cur_iter = [False for _ in range_(self.__num_dataset)]
return self
[docs] def current_iteration(self):
"""Get the index of the current iteration.
Returns
-------
cur_iter : int
The index of the current iteration.
"""
out_cur_iter = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterGetCurrentIteration(
self.handle,
ctypes.byref(out_cur_iter)))
return out_cur_iter.value
[docs] def num_model_per_iteration(self):
"""Get number of models per iteration.
Returns
-------
model_per_iter : int
The number of models per iteration.
"""
model_per_iter = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterNumModelPerIteration(
self.handle,
ctypes.byref(model_per_iter)))
return model_per_iter.value
[docs] def num_trees(self):
"""Get number of weak sub-models.
Returns
-------
num_trees : int
The number of weak sub-models.
"""
num_trees = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterNumberOfTotalModel(
self.handle,
ctypes.byref(num_trees)))
return num_trees.value
[docs] def eval(self, data, name, feval=None):
"""Evaluate for data.
Parameters
----------
data : Dataset
Data for the evaluating.
name : string
Name of the data.
feval : callable or None, optional (default=None)
Customized evaluation function.
Should accept two parameters: preds, train_data,
and return (eval_name, eval_result, is_higher_better) or list of such tuples.
For multi-class task, the preds is group by class_id first, then group by row_id.
If you want to get i-th row preds in j-th class, the access way is preds[j * num_data + i].
Returns
-------
result : list
List with evaluation results.
"""
if not isinstance(data, Dataset):
raise TypeError("Can only eval for Dataset instance")
data_idx = -1
if data is self.train_set:
data_idx = 0
else:
for i in range_(len(self.valid_sets)):
if data is self.valid_sets[i]:
data_idx = i + 1
break
# need to push new valid data
if data_idx == -1:
self.add_valid(data, name)
data_idx = self.__num_dataset - 1
return self.__inner_eval(name, data_idx, feval)
[docs] def eval_train(self, feval=None):
"""Evaluate for training data.
Parameters
----------
feval : callable or None, optional (default=None)
Customized evaluation function.
Should accept two parameters: preds, train_data,
and return (eval_name, eval_result, is_higher_better) or list of such tuples.
For multi-class task, the preds is group by class_id first, then group by row_id.
If you want to get i-th row preds in j-th class, the access way is preds[j * num_data + i].
Returns
-------
result : list
List with evaluation results.
"""
return self.__inner_eval(self.__train_data_name, 0, feval)
[docs] def eval_valid(self, feval=None):
"""Evaluate for validation data.
Parameters
----------
feval : callable or None, optional (default=None)
Customized evaluation function.
Should accept two parameters: preds, train_data,
and return (eval_name, eval_result, is_higher_better) or list of such tuples.
For multi-class task, the preds is group by class_id first, then group by row_id.
If you want to get i-th row preds in j-th class, the access way is preds[j * num_data + i].
Returns
-------
result : list
List with evaluation results.
"""
return [item for i in range_(1, self.__num_dataset)
for item in self.__inner_eval(self.name_valid_sets[i - 1], i, feval)]
[docs] def save_model(self, filename, num_iteration=None, start_iteration=0):
"""Save Booster to file.
Parameters
----------
filename : string
Filename to save Booster.
num_iteration : int or None, optional (default=None)
Index of the iteration that should be saved.
If None, if the best iteration exists, it is saved; otherwise, all iterations are saved.
If <= 0, all iterations are saved.
start_iteration : int, optional (default=0)
Start index of the iteration that should be saved.
Returns
-------
self : Booster
Returns self.
"""
if num_iteration is None:
num_iteration = self.best_iteration
_safe_call(_LIB.LGBM_BoosterSaveModel(
self.handle,
ctypes.c_int(start_iteration),
ctypes.c_int(num_iteration),
c_str(filename)))
_dump_pandas_categorical(self.pandas_categorical, filename)
return self
[docs] def shuffle_models(self, start_iteration=0, end_iteration=-1):
"""Shuffle models.
Parameters
----------
start_iteration : int, optional (default=0)
The first iteration that will be shuffled.
end_iteration : int, optional (default=-1)
The last iteration that will be shuffled.
If <= 0, means the last available iteration.
Returns
-------
self : Booster
Booster with shuffled models.
"""
_safe_call(_LIB.LGBM_BoosterShuffleModels(
self.handle,
ctypes.c_int(start_iter),
ctypes.c_int(end_iter)))
return self
[docs] def model_from_string(self, model_str, verbose=True):
"""Load Booster from a string.
Parameters
----------
model_str : string
Model will be loaded from this string.
verbose : bool, optional (default=True)
Whether to print messages while loading model.
Returns
-------
self : Booster
Loaded Booster object.
"""
if self.handle is not None:
_safe_call(_LIB.LGBM_BoosterFree(self.handle))
self._free_buffer()
self.handle = ctypes.c_void_p()
out_num_iterations = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterLoadModelFromString(
c_str(model_str),
ctypes.byref(out_num_iterations),
ctypes.byref(self.handle)))
out_num_class = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterGetNumClasses(
self.handle,
ctypes.byref(out_num_class)))
if verbose:
print('Finished loading model, total used %d iterations' % int(out_num_iterations.value))
self.__num_class = out_num_class.value
self.pandas_categorical = _load_pandas_categorical(model_str=model_str)
return self
[docs] def model_to_string(self, num_iteration=None, start_iteration=0):
"""Save Booster to string.
Parameters
----------
num_iteration : int or None, optional (default=None)
Index of the iteration that should be saved.
If None, if the best iteration exists, it is saved; otherwise, all iterations are saved.
If <= 0, all iterations are saved.
start_iteration : int, optional (default=0)
Start index of the iteration that should be saved.
Returns
-------
str_repr : string
String representation of Booster.
"""
if num_iteration is None:
num_iteration = self.best_iteration
buffer_len = 1 << 20
tmp_out_len = ctypes.c_int64(0)
string_buffer = ctypes.create_string_buffer(buffer_len)
ptr_string_buffer = ctypes.c_char_p(*[ctypes.addressof(string_buffer)])
_safe_call(_LIB.LGBM_BoosterSaveModelToString(
self.handle,
ctypes.c_int(start_iteration),
ctypes.c_int(num_iteration),
ctypes.c_int64(buffer_len),
ctypes.byref(tmp_out_len),
ptr_string_buffer))
actual_len = tmp_out_len.value
# if buffer length is not long enough, re-allocate a buffer
if actual_len > buffer_len:
string_buffer = ctypes.create_string_buffer(actual_len)
ptr_string_buffer = ctypes.c_char_p(*[ctypes.addressof(string_buffer)])
_safe_call(_LIB.LGBM_BoosterSaveModelToString(
self.handle,
ctypes.c_int(start_iteration),
ctypes.c_int(num_iteration),
ctypes.c_int64(actual_len),
ctypes.byref(tmp_out_len),
ptr_string_buffer))
ret = string_buffer.value.decode()
ret += _dump_pandas_categorical(self.pandas_categorical)
return ret
[docs] def dump_model(self, num_iteration=None, start_iteration=0):
"""Dump Booster to JSON format.
Parameters
----------
num_iteration : int or None, optional (default=None)
Index of the iteration that should be dumped.
If None, if the best iteration exists, it is dumped; otherwise, all iterations are dumped.
If <= 0, all iterations are dumped.
start_iteration : int, optional (default=0)
Start index of the iteration that should be dumped.
Returns
-------
json_repr : dict
JSON format of Booster.
"""
if num_iteration is None:
num_iteration = self.best_iteration
buffer_len = 1 << 20
tmp_out_len = ctypes.c_int64(0)
string_buffer = ctypes.create_string_buffer(buffer_len)
ptr_string_buffer = ctypes.c_char_p(*[ctypes.addressof(string_buffer)])
_safe_call(_LIB.LGBM_BoosterDumpModel(
self.handle,
ctypes.c_int(start_iteration),
ctypes.c_int(num_iteration),
ctypes.c_int64(buffer_len),
ctypes.byref(tmp_out_len),
ptr_string_buffer))
actual_len = tmp_out_len.value
# if buffer length is not long enough, reallocate a buffer
if actual_len > buffer_len:
string_buffer = ctypes.create_string_buffer(actual_len)
ptr_string_buffer = ctypes.c_char_p(*[ctypes.addressof(string_buffer)])
_safe_call(_LIB.LGBM_BoosterDumpModel(
self.handle,
ctypes.c_int(start_iteration),
ctypes.c_int(num_iteration),
ctypes.c_int64(actual_len),
ctypes.byref(tmp_out_len),
ptr_string_buffer))
ret = json.loads(string_buffer.value.decode())
ret['pandas_categorical'] = json.loads(json.dumps(self.pandas_categorical,
default=json_default_with_numpy))
return ret
[docs] def predict(self, data, num_iteration=None,
raw_score=False, pred_leaf=False, pred_contrib=False,
data_has_header=False, is_reshape=True, **kwargs):
"""Make a prediction.
Parameters
----------
data : string, numpy array, pandas DataFrame or scipy.sparse
Data source for prediction.
If string, it represents the path to txt file.
num_iteration : int or None, optional (default=None)
Limit number of iterations in the prediction.
If None, if the best iteration exists, it is used; otherwise, all iterations are used.
If <= 0, all iterations are used (no limits).
raw_score : bool, optional (default=False)
Whether to predict raw scores.
pred_leaf : bool, optional (default=False)
Whether to predict leaf index.
pred_contrib : bool, optional (default=False)
Whether to predict feature contributions.
Note
----
If you want to get more explanation for your model's predictions using SHAP values
like SHAP interaction values,
you can install shap package (https://github.com/slundberg/shap).
data_has_header : bool, optional (default=False)
Whether the data has header.
Used only if data is string.
is_reshape : bool, optional (default=True)
If True, result is reshaped to [nrow, ncol].
**kwargs
Other parameters for the prediction.
Returns
-------
result : numpy array
Prediction result.
"""
predictor = self._to_predictor(copy.deepcopy(kwargs))
if num_iteration is None:
num_iteration = self.best_iteration
return predictor.predict(data, num_iteration,
raw_score, pred_leaf, pred_contrib,
data_has_header, is_reshape)
[docs] def refit(self, data, label, decay_rate=0.9, **kwargs):
"""Refit the existing Booster by new data.
Parameters
----------
data : string, numpy array, pandas DataFrame or scipy.sparse
Data source for refit.
If string, it represents the path to txt file.
label : list, numpy 1-D array or pandas Series / one-column DataFrame
Label for refit.
decay_rate : float, optional (default=0.9)
Decay rate of refit,
will use ``leaf_output = decay_rate * old_leaf_output + (1.0 - decay_rate) * new_leaf_output`` to refit trees.
**kwargs
Other parameters for refit.
These parameters will be passed to ``predict`` method.
Returns
-------
result : Booster
Refitted Booster.
"""
if self.__set_objective_to_none:
raise LightGBMError('Cannot refit due to null objective function.')
predictor = self._to_predictor(copy.deepcopy(kwargs))
leaf_preds = predictor.predict(data, -1, pred_leaf=True)
nrow, ncol = leaf_preds.shape
train_set = Dataset(data, label, silent=True)
new_booster = Booster(self.params, train_set, silent=True)
# Copy models
_safe_call(_LIB.LGBM_BoosterMerge(
new_booster.handle,
predictor.handle))
leaf_preds = leaf_preds.reshape(-1)
ptr_data, type_ptr_data, _ = c_int_array(leaf_preds)
_safe_call(_LIB.LGBM_BoosterRefit(
new_booster.handle,
ptr_data,
ctypes.c_int(nrow),
ctypes.c_int(ncol)))
new_booster.network = self.network
new_booster.__attr = self.__attr.copy()
return new_booster
[docs] def get_leaf_output(self, tree_id, leaf_id):
"""Get the output of a leaf.
Parameters
----------
tree_id : int
The index of the tree.
leaf_id : int
The index of the leaf in the tree.
Returns
-------
result : float
The output of the leaf.
"""
ret = ctypes.c_double(0)
_safe_call(_LIB.LGBM_BoosterGetLeafValue(
self.handle,
ctypes.c_int(tree_id),
ctypes.c_int(leaf_id),
ctypes.byref(ret)))
return ret.value
def _to_predictor(self, pred_parameter=None):
"""Convert to predictor."""
predictor = _InnerPredictor(booster_handle=self.handle, pred_parameter=pred_parameter)
predictor.pandas_categorical = self.pandas_categorical
return predictor
[docs] def num_feature(self):
"""Get number of features.
Returns
-------
num_feature : int
The number of features.
"""
out_num_feature = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterGetNumFeature(
self.handle,
ctypes.byref(out_num_feature)))
return out_num_feature.value
[docs] def feature_name(self):
"""Get names of features.
Returns
-------
result : list
List with names of features.
"""
num_feature = self.num_feature()
# Get name of features
tmp_out_len = ctypes.c_int(0)
string_buffers = [ctypes.create_string_buffer(255) for i in range_(num_feature)]
ptr_string_buffers = (ctypes.c_char_p * num_feature)(*map(ctypes.addressof, string_buffers))
_safe_call(_LIB.LGBM_BoosterGetFeatureNames(
self.handle,
ctypes.byref(tmp_out_len),
ptr_string_buffers))
if num_feature != tmp_out_len.value:
raise ValueError("Length of feature names doesn't equal with num_feature")
return [string_buffers[i].value.decode() for i in range_(num_feature)]
[docs] def feature_importance(self, importance_type='split', iteration=None):
"""Get feature importances.
Parameters
----------
importance_type : string, optional (default="split")
How the importance is calculated.
If "split", result contains numbers of times the feature is used in a model.
If "gain", result contains total gains of splits which use the feature.
iteration : int or None, optional (default=None)
Limit number of iterations in the feature importance calculation.
If None, if the best iteration exists, it is used; otherwise, all trees are used.
If <= 0, all trees are used (no limits).
Returns
-------
result : numpy array
Array with feature importances.
"""
if iteration is None:
iteration = self.best_iteration
if importance_type == "split":
importance_type_int = 0
elif importance_type == "gain":
importance_type_int = 1
else:
importance_type_int = -1
result = np.zeros(self.num_feature(), dtype=np.float64)
_safe_call(_LIB.LGBM_BoosterFeatureImportance(
self.handle,
ctypes.c_int(iteration),
ctypes.c_int(importance_type_int),
result.ctypes.data_as(ctypes.POINTER(ctypes.c_double))))
if importance_type_int == 0:
return result.astype(int)
else:
return result
def __inner_eval(self, data_name, data_idx, feval=None):
"""Evaluate training or validation data."""
if data_idx >= self.__num_dataset:
raise ValueError("Data_idx should be smaller than number of dataset")
self.__get_eval_info()
ret = []
if self.__num_inner_eval > 0:
result = np.zeros(self.__num_inner_eval, dtype=np.float64)
tmp_out_len = ctypes.c_int(0)
_safe_call(_LIB.LGBM_BoosterGetEval(
self.handle,
ctypes.c_int(data_idx),
ctypes.byref(tmp_out_len),
result.ctypes.data_as(ctypes.POINTER(ctypes.c_double))))
if tmp_out_len.value != self.__num_inner_eval:
raise ValueError("Wrong length of eval results")
for i in range_(self.__num_inner_eval):
ret.append((data_name, self.__name_inner_eval[i],
result[i], self.__higher_better_inner_eval[i]))
if feval is not None:
if data_idx == 0:
cur_data = self.train_set
else:
cur_data = self.valid_sets[data_idx - 1]
feval_ret = feval(self.__inner_predict(data_idx), cur_data)
if isinstance(feval_ret, list):
for eval_name, val, is_higher_better in feval_ret:
ret.append((data_name, eval_name, val, is_higher_better))
else:
eval_name, val, is_higher_better = feval_ret
ret.append((data_name, eval_name, val, is_higher_better))
return ret
def __inner_predict(self, data_idx):
"""Predict for training and validation dataset."""
if data_idx >= self.__num_dataset:
raise ValueError("Data_idx should be smaller than number of dataset")
if self.__inner_predict_buffer[data_idx] is None:
if data_idx == 0:
n_preds = self.train_set.num_data() * self.__num_class
else:
n_preds = self.valid_sets[data_idx - 1].num_data() * self.__num_class
self.__inner_predict_buffer[data_idx] = np.zeros(n_preds, dtype=np.float64)
# avoid to predict many time in one iteration
if not self.__is_predicted_cur_iter[data_idx]:
tmp_out_len = ctypes.c_int64(0)
data_ptr = self.__inner_predict_buffer[data_idx].ctypes.data_as(ctypes.POINTER(ctypes.c_double))
_safe_call(_LIB.LGBM_BoosterGetPredict(
self.handle,
ctypes.c_int(data_idx),
ctypes.byref(tmp_out_len),
data_ptr))
if tmp_out_len.value != len(self.__inner_predict_buffer[data_idx]):
raise ValueError("Wrong length of predict results for data %d" % (data_idx))
self.__is_predicted_cur_iter[data_idx] = True
return self.__inner_predict_buffer[data_idx]
def __get_eval_info(self):
"""Get inner evaluation count and names."""
if self.__need_reload_eval_info:
self.__need_reload_eval_info = False
out_num_eval = ctypes.c_int(0)
# Get num of inner evals
_safe_call(_LIB.LGBM_BoosterGetEvalCounts(
self.handle,
ctypes.byref(out_num_eval)))
self.__num_inner_eval = out_num_eval.value
if self.__num_inner_eval > 0:
# Get name of evals
tmp_out_len = ctypes.c_int(0)
string_buffers = [ctypes.create_string_buffer(255) for i in range_(self.__num_inner_eval)]
ptr_string_buffers = (ctypes.c_char_p * self.__num_inner_eval)(*map(ctypes.addressof, string_buffers))
_safe_call(_LIB.LGBM_BoosterGetEvalNames(
self.handle,
ctypes.byref(tmp_out_len),
ptr_string_buffers))
if self.__num_inner_eval != tmp_out_len.value:
raise ValueError("Length of eval names doesn't equal with num_evals")
self.__name_inner_eval = \
[string_buffers[i].value.decode() for i in range_(self.__num_inner_eval)]
self.__higher_better_inner_eval = \
[name.startswith(('auc', 'ndcg@', 'map@')) for name in self.__name_inner_eval]
[docs] def attr(self, key):
"""Get attribute string from the Booster.
Parameters
----------
key : string
The name of the attribute.
Returns
-------
value : string or None
The attribute value.
Returns None if attribute does not exist.
"""
return self.__attr.get(key, None)
[docs] def set_attr(self, **kwargs):
"""Set attributes to the Booster.
Parameters
----------
**kwargs
The attributes to set.
Setting a value to None deletes an attribute.
Returns
-------
self : Booster
Booster with set attributes.
"""
for key, value in kwargs.items():
if value is not None:
if not isinstance(value, string_type):
raise ValueError("Only string values are accepted")
self.__attr[key] = value
else:
self.__attr.pop(key, None)
return self