Check if a directory exists in a zip file with Python

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Initially I was thinking of using os.path.isdir but I don't think this works for zip files. Is there a way to peek into the zip file and verify that this directory exists? I would like to prevent using unzip -l "$@" as much as possible, but if that's the only solution then I guess I have no choice.

unzip python
4 Answers

for python(>=3.6):

this is how the is_dir() implemented in python source code:

def is_dir(self):
    """Return True if this archive member is a directory."""
    return self.filename[-1] == '/'

It simply checks if the filename ends with a slash /, Can't tell if this will work correctly in some certain circumstances(so IMO it is badly implemented).

for python(<3.6):

as print(zipinfo) will show filemode but no corrsponding property or field is provided, I dive into zipfile module source code and found how it is implemented. (see def __repr__(self): https://github.com/python/cpython/blob/3.6/Lib/zipfile.py)

possibly a bad idea but it will work:

if you want something simple and easy, this will work in most cases but it may fail because in some cases this field will not be printed.

def is_dir(zipinfo):
    return "filemode='d" in zipinfo.__repr__()

Finally:

my solution is to check file mode manually and decide if the referenced file is actually a directory inspired by https://github.com/python/cpython/blob/3.6/Lib/zipfile.py line 391.

def is_dir(fileinfo):
    hi = fileinfo.external_attr >> 16
    return (hi & 0x4000) > 0
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