compress

typhon.files.compress(filename, fmt=None, tmpdir=None)[source]

Compress a file after writing to it.

Supported compression formats are: gzip, bzip2, zip, and lzma (Python 3.3 or newer only).

This function is tailored for use in a with statement. It uses a context manager to automatically create a temporary file to which the data can be written. After writing to the file, it compresses and renames it.

TODO: Preferably, it should be possible to write to the compressed file directly instead of copying it.

Parameters

  • filename – The path and name of the compressed that should be created. The filename’s extension decides to which format the file will be compressed (look at fmt for a list).

  • fmt – If want to specify the compression format without using the filename’s extension, use this argument. * zip: Uses the standard zip library. * bz2: Uses the bz2 library. * gz: Uses the GNU zip library. * xz: Uses the lzma format.

  • tmpdir (str) – Path to directory for temporary storage of the uncompressed file. The directory must exist. The default is the temporary dir of the system.

Yields

Generator containing the path to the temporary file.

Examples

>>> with typhon.files.compress('datafile.nc.gz') as file:
>>>     f = netCDF4.Dataset(file, 'w')
>>>     #...