mindspore.mindrecord

Introduction of MindRecord.

MindRecord is a module to implement reading, writing, searching and converting for MindSpore format dataset. Users could use the FileWriter API to generate MindRecord data and use the MindDataset API to load MindRecord data. Users could also convert other format datasets to mindrecord data through corresponding sub-module.

class mindspore.mindrecord.Cifar100ToMR(source, destination)[source]

A class to transform from cifar100 to MindRecord.

Note

For details about Examples, please refer to Converting the CIFAR-10 Dataset.

Parameters

source (str) – The cifar100 directory to be transformed.
destination (str) – MindRecord file path to transform into, ensure that no file with the same name exists in the directory.

Raises

ValueError – If source or destination is invalid.

run(fields=None)[source]

Execute transformation from cifar100 to MindRecord.

Parameters: fields (list[str]) – A list of index field, e.g.[“fine_label”, “coarse_label”]. Default: None.
Returns: MSRStatus, SUCCESS or FAILED.

transform(fields=None)[source]

Encapsulate the run function to exit normally

Parameters: fields (list[str]) – A list of index field, e.g.[“fine_label”, “coarse_label”]. Default: None.
Returns: MSRStatus, SUCCESS or FAILED.

class mindspore.mindrecord.Cifar10ToMR(source, destination)[source]

A class to transform from cifar10 to MindRecord.

Note

For details about Examples, please refer to Converting the CIFAR-10 Dataset.

Parameters

source (str) – The cifar10 directory to be transformed.
destination (str) – MindRecord file path to transform into, ensure that no file with the same name exists in the directory.

Raises

ValueError – If source or destination is invalid.

run(fields=None)[source]

Execute transformation from cifar10 to MindRecord.

Parameters: fields (list[str], optional) – A list of index fields. Default: None.
Returns: MSRStatus, SUCCESS or FAILED.

transform(fields=None)[source]

Encapsulate the run function to exit normally

Parameters: fields (list[str], optional) – A list of index fields. Default: None.
Returns: MSRStatus, SUCCESS or FAILED.

class mindspore.mindrecord.CsvToMR(source, destination, columns_list=None, partition_number=1)[source]

A class to transform from csv to MindRecord.

Note

For details about Examples, please refer to Converting CSV Dataset.

Parameters

source (str) – The file path of csv.
destination (str) – The MindRecord file path to transform into, ensure that no file with the same name exists in the directory.
columns_list (list[str], optional) – A list of columns to be read. Default: None.
partition_number (int, optional) – The partition size, Default: 1.

Raises

ValueError – If source, destination, partition_number is invalid.
RuntimeError – If columns_list is invalid.

run()[source]

Execute transformation from csv to MindRecord.

Returns: MSRStatus, SUCCESS or FAILED.

transform()[source]

Encapsulate the run function to exit normally.

Returns: MSRStatus, SUCCESS or FAILED.

class mindspore.mindrecord.FileReader(file_name, num_consumer=4, columns=None, operator=None)[source]

Class to read MindRecord files.

Note

If file_name is a file path, it tries to load all MindRecord files generated in a conversion, and throws an exception if a MindRecord file is missing. If file_name is file path list, only the MindRecord files in the list are loaded.

Parameters

file_name (str, list[str]) – One of MindRecord file path or file path list.
num_consumer (int, optional) – Number of reader workers which load data. Default: 4. It should not be smaller than 1 or larger than the number of processor cores.
columns (list[str], optional) – A list of fields where corresponding data would be read. Default: None.
operator (int, optional) – Reserved parameter for operators. Default: None.

Raises

ParamValueError – If file_name, num_consumer or columns is invalid.

close()[source]: Stop reader worker and close file.

get_next()[source]

Yield a batch of data according to columns at a time.

Returns: dict, a batch whose keys are the same as columns.
Raises: MRMUnsupportedSchemaError – If schema is invalid.

class mindspore.mindrecord.FileWriter(file_name, shard_num=1, overwrite=False)[source]

Class to write user defined raw data into MindRecord files.

Note

After the MindRecord file is generated, if the file name is changed, the file may fail to be read.

Parameters

file_name (str) – File name of MindRecord file.
shard_num (int, optional) – The Number of MindRecord files. It should be between [1, 1000]. Default: 1.
overwrite (bool, optional) – Whether to overwrite if the file already exists. Default: False.

Raises

ParamValueError – If file_name or shard_num or overwrite is invalid.

Examples

>>> from mindspore.mindrecord import FileWriter
>>> schema_json = {"file_name": {"type": "string"}, "label": {"type": "int32"}, "data": {"type": "bytes"}}
>>> indexes = ["file_name", "label"]
>>> data = [{"file_name": "1.jpg", "label": 0,
...          "data": b"\x10c\xb3w\xa8\xee$o&<q\x8c\x8e(\xa2\x90\x90\x96\xbc\xb1\x1e\xd4QER\x13?\xff"},
...         {"file_name": "2.jpg", "label": 56,
...          "data": b"\xe6\xda\xd1\xae\x07\xb8>\xd4\x00\xf8\x129\x15\xd9\xf2q\xc0\xa2\x91YFUO\x1dsE1"},
...         {"file_name": "3.jpg", "label": 99,
...          "data": b"\xaf\xafU<\xb8|6\xbd}\xc1\x99[\xeaj+\x8f\x84\xd3\xcc\xa0,i\xbb\xb9-\xcdz\xecp{T\xb1"}]
>>> writer = FileWriter(file_name="test.mindrecord", shard_num=1, overwrite=True)
>>> writer.add_schema(schema_json, "test_schema")
0
>>> writer.add_index(indexes)
MSRStatus.SUCCESS
>>> writer.write_raw_data(data)
MSRStatus.SUCCESS
>>> writer.commit()
MSRStatus.SUCCESS

add_index(index_fields)[source]

Select index fields from schema to accelerate reading.

Note

The index fields should be primitive type. e.g. int/float/str. If the function is not called, the fields of the primitive type in schema are set as indexes by default.

Please refer to the Examples of class: mindspore.mindrecord.FileWriter.

Parameters

index_fields (list[str]) – fields from schema.

Returns

MSRStatus, SUCCESS or FAILED.

Raises

ParamTypeError – If index field is invalid.
MRMDefineIndexError – If index field is not primitive type.
MRMAddIndexError – If failed to add index field.
MRMGetMetaError – If the schema is not set or failed to get meta.

add_schema(content, desc=None)[source]

The schema is added to describe the raw data to be written.

Note

Please refer to the Examples of class: mindspore.mindrecord.FileWriter.

Parameters

content (dict) – Dictionary of schema content.
desc (str, optional) – String of schema description, Default: None.

Returns

int, schema id.

Raises

MRMInvalidSchemaError – If schema is invalid.
MRMBuildSchemaError – If failed to build schema.
MRMAddSchemaError – If failed to add schema.

commit()[source]

Flush data in memory to disk and generate the corresponding database files.

Note

Please refer to the Examples of class: mindspore.mindrecord.FileWriter.

Returns

MSRStatus, SUCCESS or FAILED.

Raises

MRMOpenError – If failed to open MindRecord file.
MRMSetHeaderError – If failed to set header.
MRMIndexGeneratorError – If failed to create index generator.
MRMGenerateIndexError – If failed to write to database.
MRMCommitError – If failed to flush data to disk.

open_and_set_header()[source]

Open writer and set header which stores meta information. The function is only used for parallel writing and is called before the write_raw_data.

Returns

MSRStatus, SUCCESS or FAILED.

Raises

MRMOpenError – If failed to open MindRecord file.
MRMSetHeaderError – If failed to set header.

classmethod open_for_append(file_name)[source]

Open MindRecord file and get ready to append data.

Parameters

file_name (str) – String of MindRecord file name.

Returns

FileWriter, file writer object for the opened MindRecord file.

Raises

ParamValueError – If file_name is invalid.
FileNameError – If path contains invalid characters.
MRMOpenError – If failed to open MindRecord file.
MRMOpenForAppendError – If failed to open file for appending data.

Examples

>>> from mindspore.mindrecord import FileWriter
>>> schema_json = {"file_name": {"type": "string"}, "label": {"type": "int32"}, "data": {"type": "bytes"}}
>>> data = [{"file_name": "1.jpg", "label": 0,
...          "data": b"\x10c\xb3w\xa8\xee$o&<q\x8c\x8e(\xa2\x90\x90\x96\xbc\xb1\x1e\xd4QER\x13?\xff"}]
>>> writer = FileWriter(file_name="test.mindrecord", shard_num=1, overwrite=True)
>>> writer.add_schema(schema_json, "test_schema")
0
>>> writer.write_raw_data(data)
MSRStatus.SUCCESS
>>> writer.commit()
MSRStatus.SUCCESS
>>> write_append = FileWriter.open_for_append("test.mindrecord")
>>> write_append.write_raw_data(data)
MSRStatus.SUCCESS
>>> write_append.commit()
MSRStatus.SUCCESS

set_header_size(header_size)[source]

Set the size of header which contains shard information, schema information, page meta information, etc. The larger a header, the more data the MindRecord file can store. If the size of header is larger than the default size (16MB), users need to call the API to set a proper size.

Parameters: header_size (int) – Size of header, between 16*1024(16KB) and 128*1024*1024(128MB).
Returns: MSRStatus, SUCCESS or FAILED.
Raises: MRMInvalidHeaderSizeError – If failed to set header size.

Examples

>>> from mindspore.mindrecord import FileWriter
>>> writer = FileWriter(file_name="test.mindrecord", shard_num=1)
>>> writer.set_header_size(1 << 25) # 32MB
MSRStatus.SUCCESS

set_page_size(page_size)[source]

Set the size of page that represents the area where data is stored, and the areas are divided into two types: raw page and blob page. The larger a page, the more data the page can store. If the size of a sample is larger than the default size (32MB), users need to call the API to set a proper size.

Parameters: page_size (int) – Size of page, between 32*1024(32KB) and 256*1024*1024(256MB).
Returns: MSRStatus, SUCCESS or FAILED.
Raises: MRMInvalidPageSizeError – If failed to set page size.

Examples

>>> from mindspore.mindrecord import FileWriter
>>> writer = FileWriter(file_name="test.mindrecord", shard_num=1)
>>> writer.set_page_size(1 << 26) # 128MB
MSRStatus.SUCCESS

write_raw_data(raw_data, parallel_writer=False)[source]

Convert raw data into a series of consecutive MindRecord files after the raw data is verified against the schema.

Note

Please refer to the Examples of class: mindspore.mindrecord.FileWriter.

Parameters

raw_data (list[dict]) – List of raw data.
parallel_writer (bool, optional) – Write raw data in parallel if it equals to True. Default: False.

Returns

MSRStatus, SUCCESS or FAILED.

Raises

ParamTypeError – If index field is invalid.
MRMOpenError – If failed to open MindRecord file.
MRMValidateDataError – If data does not match blob fields.
MRMSetHeaderError – If failed to set header.
MRMWriteDatasetError – If failed to write dataset.

class mindspore.mindrecord.ImageNetToMR(map_file, image_dir, destination, partition_number=1)[source]

A class to transform from imagenet to MindRecord.

Parameters

map_file (str) –
The map file that indicates label. The map file content should be like this:
```
n02119789 0
n02100735 1
n02110185 2
n02096294 3
```
image_dir (str) – Image directory contains n02119789, n02100735, n02110185 and n02096294 directory.
destination (str) – MindRecord file path to transform into, ensure that no file with the same name exists in the directory.
partition_number (int, optional) – The partition size. Default: 1.

Raises

ValueError – If map_file, image_dir or destination is invalid.

run()[source]

Execute transformation from imagenet to MindRecord.

Returns: MSRStatus, SUCCESS or FAILED.

transform()[source]

Encapsulate the run function to exit normally.

Returns: MSRStatus, SUCCESS or FAILED.

class mindspore.mindrecord.MindPage(file_name, num_consumer=4)[source]

Class to read MindRecord files in pagination.

Parameters

file_name (Union[str, list[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.

property candidate_fields

Return candidate category fields.

Returns: list[str], by which data could be grouped.

property category_field

Getter function for category fields.

Returns: list[str], by which data could be grouped.

get_category_fields()[source]

Return candidate category fields.

Returns: list[str], by which data could be grouped.

read_at_page_by_id(category_id, page, num_row)[source]

Query by category id in pagination.

Parameters

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.

read_at_page_by_name(category_name, page, num_row)[source]

Query by category name in pagination.

Parameters

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.

read_category_info()[source]

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.

set_category_field(category_field)[source]

Set category field for reading.

Note

Should be a candidate category field.

Parameters: category_field (str) – String of category field name.
Returns: MSRStatus, SUCCESS or FAILED.

class mindspore.mindrecord.MnistToMR(source, destination, partition_number=1)[source]

A class to transform from Mnist to MindRecord.

Parameters

source (str) – Directory that contains t10k-images-idx3-ubyte.gz, train-images-idx3-ubyte.gz, t10k-labels-idx1-ubyte.gz and train-labels-idx1-ubyte.gz.
destination (str) – MindRecord file path to transform into, ensure that no file with the same name exists in the directory.
partition_number (int, optional) – The partition size. Default: 1.

Raises

ValueError – If source, destination, partition_number is invalid.

run()[source]

Execute transformation from Mnist to MindRecord.

Returns: MSRStatus, SUCCESS or FAILED.

transform()[source]

Encapsulate the run function to exit normally.

Returns: MSRStatus, SUCCESS or FAILED.

class mindspore.mindrecord.TFRecordToMR(source, destination, feature_dict, bytes_fields=None)[source]

A class to transform from TFRecord to MindRecord.

Note

For details about Examples, please refer to Converting TFRecord Dataset.

Parameters

source (str) – TFRecord file to be transformed.
destination (str) – MindRecord file path to transform into, ensure that no file with the same name exists in the directory.
feature_dict (dict[str, FixedLenFeature]) – Dictionary that states the feature type, and FixedLenFeature is supported.
bytes_fields (list[str], optional) – The bytes fields which are in feature_dict and can be images bytes. Default: None.

Raises

ValueError – If parameter is invalid.
Exception – when tensorflow module is not found or version is not correct.

run()[source]

Execute transformation from TFRecord to MindRecord.

Returns: MSRStatus, SUCCESS or FAILED.

tfrecord_iterator()[source]

Yield a dictionary whose keys are fields in schema.

Returns: dict, data dictionary whose keys are the same as columns.

tfrecord_iterator_oldversion()[source]

Yield a dict with key to be fields in schema, and value to be data. This function is for old version tensorflow whose version number < 2.1.0

Returns: dict, data dictionary whose keys are the same as columns.

transform()[source]

Encapsulate the run function to exit normally.

Returns: MSRStatus, SUCCESS or FAILED.