mindspore.dataset.CSVDataset
- class mindspore.dataset.CSVDataset(dataset_files, field_delim=',', column_defaults=None, column_names=None, num_samples=None, num_parallel_workers=None, shuffle=Shuffle.GLOBAL, num_shards=None, shard_id=None, cache=None)[source]
A source dataset that reads and parses comma-separated values (CSV) files as dataset.
The columns of generated dataset depend on the source CSV files.
- Parameters
dataset_files (Union[str, list[str]]) – String or list of files to be read or glob strings to search for a pattern of files. The list will be sorted in a lexicographical order.
field_delim (str, optional) – A string that indicates the char delimiter to separate fields. Default: ‘,’.
column_defaults (list, optional) – List of default values for the CSV field. Default: None. Each item in the list is either a valid type (float, int, or string). If this is not provided, treats all columns as string type.
column_names (list[str], optional) – List of column names of the dataset. Default: None. If this is not provided, infers the column_names from the first row of CSV file.
num_samples (int, optional) – The number of samples to be included in the dataset. Default: None, will include all images.
num_parallel_workers (int, optional) – Number of workers to read the data. Default: None, number set in the config.
shuffle (Union[bool, Shuffle], optional) –
Perform reshuffling of the data every epoch. Default: Shuffle.GLOBAL. Bool type and Shuffle enum are both supported to pass in. If shuffle is False, no shuffling will be performed. If shuffle is True, performs global shuffle. There are three levels of shuffling, desired shuffle enum defined by mindspore.dataset.Shuffle.
Shuffle.GLOBAL: Shuffle both the files and samples, same as setting shuffle to True.
Shuffle.FILES: Shuffle files only.
num_shards (int, optional) – Number of shards that the dataset will be divided into. Default: None. When this argument is specified, num_samples reflects the maximum sample number of per shard.
shard_id (int, optional) – The shard ID within num_shards . Default: None. This argument can only be specified when num_shards is also specified.
cache (DatasetCache, optional) – Use tensor caching service to speed up dataset processing. More details: Single-Node Data Cache . Default: None, which means no cache is used.
- Raises
RuntimeError – If dataset_files are not valid or do not exist.
ValueError – If field_delim is invalid.
ValueError – If num_parallel_workers exceeds the max thread numbers.
RuntimeError – If num_shards is specified but shard_id is None.
RuntimeError – If shard_id is specified but num_shards is None.
ValueError – If shard_id is invalid (< 0 or >= num_shards).
Examples
>>> csv_dataset_dir = ["/path/to/csv_dataset_file"] # contains 1 or multiple csv files >>> dataset = ds.CSVDataset(dataset_files=csv_dataset_dir, column_names=['col1', 'col2', 'col3', 'col4'])
Pre-processing Operation
Apply a function in this dataset. |
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Concatenate the dataset objects in the input list. |
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Filter dataset by prediction. |
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Map func to each row in dataset and flatten the result. |
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Apply each operation in operations to this dataset. |
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The specified columns will be selected from the dataset and passed into the pipeline with the order specified. |
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Rename the columns in input datasets. |
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Repeat this dataset count times. |
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Reset the dataset for next epoch. |
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Save the dynamic data processed by the dataset pipeline in common dataset format. |
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Shuffle the dataset by creating a cache with the size of buffer_size . |
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Skip the first N elements of this dataset. |
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Split the dataset into smaller, non-overlapping datasets. |
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Takes at most given numbers of elements from the dataset. |
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Zip the datasets in the sense of input tuple of datasets. |
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Function to create a SentencePieceVocab from source dataset. |
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Function to create a Vocab from source dataset. |
Batch
Combine batch_size number of consecutive rows into batch which apply per_batch_map to the samples first. |
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Bucket elements according to their lengths. |
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Combine batch_size number of consecutive rows into batch which apply pad_info to the samples first. |
Iterator
Create an iterator over the dataset. |
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Create an iterator over the dataset. |
Attribute
Return the size of batch. |
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Return the class index. |
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Return the names of the columns in dataset. |
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Return the number of batches in an epoch. |
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Get the replication times in RepeatDataset. |
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Get the column index, which represents the corresponding relationship between the data column order and the network when using the sink mode. |
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Get the number of classes in a dataset. |
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Get the shapes of output data. |
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Get the types of output data. |
Apply Sampler
Add a child sampler for the current dataset. |
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Replace the last child sampler of the current dataset, remaining the parent sampler unchanged. |
Others
Return a transferred Dataset that transfers data through a device. |
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Release a blocking condition and trigger callback with given data. |
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Add a blocking condition to the input Dataset and a synchronize action will be applied. |
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Serialize a pipeline into JSON string and dump into file if filename is provided. |