Class ParquetFile

python/pyarrow/parquet/core.py:208–711

Reader interface for a single Parquet file. Parameters ---------- source : str, pathlib.Path, pyarrow.NativeFile, or file-like object Readable source. For passing bytes or buffer-like file containing a Parquet file, use pyarrow.BufferReader. metadata : FileMetaD

class ParquetFile:
    """
    Reader interface for a single Parquet file.

    Parameters
    ----------
    source : str, pathlib.Path, pyarrow.NativeFile, or file-like object
        Readable source. For passing bytes or buffer-like file containing a
        Parquet file, use pyarrow.BufferReader.
    metadata : FileMetaData, default None
        Use existing metadata object, rather than reading from file.
    common_metadata : FileMetaData, default None
        Will be used in reads for pandas schema metadata if not found in the
        main file's metadata, no other uses at the moment.
    read_dictionary : list
        List of column names to read directly as DictionaryArray.
    binary_type : pyarrow.DataType, default None
        If given, Parquet binary columns will be read as this datatype.
        This setting is ignored if a serialized Arrow schema is found in
        the Parquet metadata.
    list_type : subclass of pyarrow.DataType, default None
        If given, non-MAP repeated columns will be read as an instance of
        this datatype (either pyarrow.ListType or pyarrow.LargeListType).
        This setting is ignored if a serialized Arrow schema is found in
        the Parquet metadata.
    memory_map : bool, default False
        If the source is a file path, use a memory map to read file, which can
        improve performance in some environments.
    buffer_size : int, default 0
        If positive, perform read buffering when deserializing individual
        column chunks. Otherwise IO calls are unbuffered.
    pre_buffer : bool, default True
        Coalesce and issue file reads in parallel to improve performance on
        high-latency filesystems (e.g. S3, GCS). If True, Arrow will use a
        background I/O thread pool. If using a filesystem layer that itself
        performs readahead (e.g. fsspec's S3FS), disable readahead for best
        results. Set to False if you want to prioritize minimal memory usage
        over maximum speed.
    coerce_int96_timestamp_unit : str, default None
        Cast timestamps that are stored in INT96 format to a particular
        resolution (e.g. 'ms'). Setting to None is equivalent to 'ns'
        and therefore INT96 timestamps will be inferred as timestamps
        in nanoseconds.
    decryption_properties : FileDecryptionProperties, default None
        File decryption properties for Parquet Modular Encryption.
    thrift_string_size_limit : int, default None
        If not None, override the maximum total string size allocated
        when decoding Thrift structures. The default limit should be
        sufficient for most Parquet files.
    thrift_container_size_limit : int, default None
        If not None, override the maximum total size of containers allocated
        when decoding Thrift structures. The default limit should be
        sufficient for most Parquet files.
    filesystem : FileSystem, default None
        If nothing passed, will be inferred based on path.
        Path will try to be found in the local on-disk filesystem otherwise
        it will be parsed as an URI to determine the filesystem.
    page_checksum_verification : bool, default False