This is what gzip.open does for instance: https://github.com/python/cpython/blob/d7334e2c2012defaf7aae920d6a56689464509d1/Lib/gzip.py#L60
I also made sure the threaded libraries do this: https://github.com/pycompression/python-isal/blob/970c141a4976276c8254310474db1038d63000ce/src/isal/igzip_threaded.py#L78
PipedCompressionProgram can also do this for writing files. For reading files, it is not possible however.
In any case, for most of the backends, processing a filehandle rather than a file is possible. This will make it easier to chain xopen to other open methods. See: marcelm/cutadapt#761
This is what
gzip.opendoes for instance: https://github.com/python/cpython/blob/d7334e2c2012defaf7aae920d6a56689464509d1/Lib/gzip.py#L60I also made sure the threaded libraries do this: https://github.com/pycompression/python-isal/blob/970c141a4976276c8254310474db1038d63000ce/src/isal/igzip_threaded.py#L78
PipedCompressionProgram can also do this for writing files. For reading files, it is not possible however.
In any case, for most of the backends, processing a filehandle rather than a file is possible. This will make it easier to chain xopen to other open methods. See: marcelm/cutadapt#761