只需检查文件名末尾的/"即可.

Just check the filename with "/" at the end of it.

import zipfile

def isdir(z, name):
    return any(x.startswith("%s/" % name.rstrip("/")) for x in z.namelist())

f = zipfile.ZipFile("sample.zip", "r")
print isdir(f, "a")
print isdir(f, "a/b")
print isdir(f, "a/X")

你用这条线

any(x.startswith("%s/" % name.rstrip("/")) for x in z.namelist())

因为存档可能不明确包含目录；只是一个带有目录名称的路径.

because it is possible that archive contains no directory explicitly; just a path with a directory name.

执行结果:

$ mkdir -p a/b/c/d
$ touch a/X
$ zip -r sample.zip a
adding: a/ (stored 0%)
adding: a/X (stored 0%)
adding: a/b/ (stored 0%)
adding: a/b/c/ (stored 0%)
adding: a/b/c/d/ (stored 0%)

$ python z.py
True
True
False