Source code for mindspore.mindrecord.mindpage

# Copyright 2019-2021 Huawei Technologies Co., Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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# http://www.apache.org/licenses/LICENSE-2.0
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# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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# ==============================================================================
"""
This module is to support reading page from MindRecord.
"""

from mindspore import log as logger
from .shardsegment import ShardSegment
from .shardutils import check_parameter
from .common.exceptions import ParamValueError, ParamTypeError, MRMDefineCategoryError

__all__ = ['MindPage']


[docs]class MindPage: """ Class to read MindRecord files in pagination. Args: file_name (str): One of MindRecord files or a file list. num_consumer(int, optional): The number of reader workers which load data. Default: 4. It should not be smaller than 1 or larger than the number of processor cores. Raises: ParamValueError: If `file_name`, `num_consumer` or columns is invalid. MRMInitSegmentError: If failed to initialize ShardSegment. """ @check_parameter def __init__(self, file_name, num_consumer=4): self._segment = ShardSegment() self._segment.open(file_name, num_consumer) self._category_field = None self._candidate_fields = [field[:field.rfind('_')] for field in self._segment.get_category_fields()] @property def candidate_fields(self): """ Return candidate category fields. Returns: list[str], by which data could be grouped. """ return self._candidate_fields
[docs] def get_category_fields(self): """ Return candidate category fields. Returns: list[str], by which data could be grouped. """ logger.warning("WARN_DEPRECATED: The usage of get_category_fields is deprecated." " Please use candidate_fields") return self.candidate_fields
[docs] def set_category_field(self, category_field): """ Set category field for reading. Note: Should be a candidate category field. Args: category_field (str): String of category field name. Returns: MSRStatus, SUCCESS or FAILED. """ logger.warning("WARN_DEPRECATED: The usage of set_category_field is deprecated." " Please use category_field") if not category_field or not isinstance(category_field, str): raise ParamTypeError('category_fields', 'str') if category_field not in self._candidate_fields: raise MRMDefineCategoryError("Field '{}' is not a candidate category field.".format(category_field)) return self._segment.set_category_field(category_field)
@property def category_field(self): """ Getter function for category fields. Returns: list[str], by which data could be grouped. """ return self._category_field @category_field.setter def category_field(self, category_field): """ Setter function for category field. Returns: MSRStatus, SUCCESS or FAILED. """ if not category_field or not isinstance(category_field, str): raise ParamTypeError('category_fields', 'str') if category_field not in self._candidate_fields: raise MRMDefineCategoryError("Field '{}' is not a candidate category field.".format(category_field)) self._category_field = category_field return self._segment.set_category_field(self._category_field)
[docs] def read_category_info(self): """ Return category information when data is grouped by indicated category field. Returns: str, description of group information. Raises: MRMReadCategoryInfoError: If failed to read category information. """ return self._segment.read_category_info()
[docs] def read_at_page_by_id(self, category_id, page, num_row): """ Query by category id in pagination. Args: category_id (int): Category id, referred to the return of `read_category_info`. page (int): Index of page. num_row (int): Number of rows in a page. Returns: list[dict], data queried by category id. Raises: ParamValueError: If any parameter is invalid. MRMFetchDataError: If failed to fetch data by category. MRMUnsupportedSchemaError: If schema is invalid. """ if not isinstance(category_id, int) or category_id < 0: raise ParamValueError("Category id should be int and greater than or equal to 0.") if not isinstance(page, int) or page < 0: raise ParamValueError("Page should be int and greater than or equal to 0.") if not isinstance(num_row, int) or num_row <= 0: raise ParamValueError("num_row should be int and greater than 0.") return self._segment.read_at_page_by_id(category_id, page, num_row)
[docs] def read_at_page_by_name(self, category_name, page, num_row): """ Query by category name in pagination. Args: category_name (str): String of category field's value, referred to the return of `read_category_info`. page (int): Index of page. num_row (int): Number of row in a page. Returns: list[dict], data queried by category name. """ if not isinstance(category_name, str): raise ParamValueError("Category name should be str.") if not isinstance(page, int) or page < 0: raise ParamValueError("Page should be int and greater than or equal to 0.") if not isinstance(num_row, int) or num_row <= 0: raise ParamValueError("num_row should be int and greater than 0.") return self._segment.read_at_page_by_name(category_name, page, num_row)