ZipFile does not store any text inside an archived file

The following code results in the file found in the zip being empty, instead of having some text in it:

def func(path):
    with tempfile.NamedTemporaryFile() as f:
        f.write('some text')
        with zipfile.ZipFile(path + '.zip', 'w', zipfile.ZIP_DEFLATED) as zf:
            zf.write((f.name), path)

Answer

Add flush to the file object:

def func(path):
    with tempfile.NamedTemporaryFile() as f:
        f.write('some text')
        f.flush()  # <-- lifesaver
        with zipfile.ZipFile(path + '.zip', 'w', zipfile.ZIP_DEFLATED) as zf:
            zf.write((f.name), path)

This problem also affects normal (non-temporary) files, so they’ll also need the flush treatment:

def func(path):
    with open(path, 'w') as f:
        f.write('some text')
        f.flush()  # <-- lifesaver
        with zipfile.ZipFile(path + '.zip', 'w', zipfile.ZIP_DEFLATED) as zf:
            zf.write(path)

Alternatively, de-denting the 2nd with block would avoid having to use flush since a file gets closed automatically when that block exits, increasing the chance of it being flushed:

def func(path):
    with open(path, 'w') as f:
        f.write('some text')
    with zipfile.ZipFile(path + '.zip', 'w', zipfile.ZIP_DEFLATED) as zf:
        zf.write(path)

Note that this will only work for the 2nd example, but not the 1st; see tempfile docs for the reason why.