[Python] Closing star/cif files after opening

[paulkorir]

This is in reference to the examples in the documentation e.g. https://gemmi.readthedocs.io/en/latest/cif.html#python. Is there a way to close files after they are opened that is not documented? I've browsed the source code and see that the Python wrappers directly reference the C++, which has no explicit file closing method. The danger is that it is likely to end up with too many opened handles.

Kindly assist.

Paul K

[paulkorir]

I propose that the best way to handle this is to use the cif.read_string(...) method to a file handle within a context manager.

from gemmi import cif

with open("file.star") as f:
    doc = cif.read_string(f.read())

which guarantees that the file will be closed.

[wojdyr]

The functions in Python bindings that are reading files, they open a file, read the content, and close the file. They should be more efficient than reading the file as string in Python.

[paulkorir]

Great! It wasn't obvious to me. It would be a good titbit to include in the documentation lest anyone ask this again.