# uproot.compression.decompress

Defined in uproot.compression on line 365.

uproot.compression.decompress(chunk, cursor, context, compressed_bytes, uncompressed_bytes, block_info=None)
  Parameters:

    - chunk (uproot.source.chunk.Chunk) – Buffer of contiguous data from the file uproot.source.chunk.Source.

    - cursor (uproot.Cursor) – Current position in that `chunk`.

    - context (dict) – Auxiliary data used in deserialization.

    - compressed_bytes (int) – Number of compressed bytes to decompress.

    - uncompressed_bytes (int) – Number of uncompressed bytes to expect after decompression.

    - block_info (None or empty list) – List to fill with `(compression type class, num compressed bytes, num uncompressed bytes)` observed in each compressed block.

  Decompresses `compressed_bytes` of a uproot.source.chunk.Chunk of data, starting at the `cursor`.

  This function parses ROOT’s 9-byte compression headers (17 bytes for LZ4 because it includes a checksum), combining blocks if there are more than one, returning the result as a new uproot.source.chunk.Chunk.