is there anyway to make a file inside a zip file seekable in Python without reading it to memory?
I tried the obvious procedure but I get an error since the file is not seekable:
In [74]: inputZipFile = zipfile.ZipFile("linear_g_LAN2A_F_3keV_1MeV_30_small.zip", 'r')
In [76]: inputCSVFile = inputZipFile.open(inputZipFile.namelist()[0], 'r')
In [77]: inputCSVFile
Out[77]: <zipfile.ZipExtFile at 0x102f5fad0>
In [78]: inputCSVFile.se
inputCSVFile.seek inputCSVFile.seekable
In [78]: inputCSVFile.seek(0)
---------------------------------------------------------------------------
UnsupportedOperation Traceback (most recent call last)
<ipython-input-78-f1f9795b3d55> in <module>()
----> 1 inputCSVFile.seek(0)
UnsupportedOperation: seek
There is no way to do so for all zip files. DEFLATE is a stream compression algorithm, which means that there is no way to decompress arbitrary parts of the file without having decompressed everything before it. It could possibly be implemented for files that have been stored, but then you get in the unfavorable position where some entries are seekable and others aren't.
ZipExtFile is now seekable :
https://bugs.python.org/issue22908 https://github.com/python/cpython/commit/066df4fd454d6ff9be66e80b2a65995b10af174f
来源：https://stackoverflow.com/questions/12821961/seek-a-file-within-a-zip-file-in-python-without-passing-it-to-memory