[pypy-issue] [issue1429] CSV module is slow
mattip
tracker at bugs.pypy.org
Mon Jan 6 14:06:28 CET 2014
mattip <matti.picus at gmail.com> added the comment:
PyPY on Windows is still slow, but the problem seems to be reading from the
file. By using the csvtest_preload.py to read the file into a list of strings,
the times improve greatly. This points to IO problems with Windows more than
parsing problems with CSV
csvtest.py -
reading took 1.986 seconds
writing took 0.411 seconds
complete took 2.397 seconds
csvtest_preload.py
reading took 0.292 seconds
writing took 0.243 seconds
complete took 0.535 seconds
----------
nosy: +mattip
status: resolved -> chatting
________________________________________
PyPy bug tracker <tracker at bugs.pypy.org>
<https://bugs.pypy.org/issue1429>
________________________________________
-------------- next part --------------
import csv
import time
with open('airports.csv') as file_in:
lines = file_in.readlines()
for i in range(10):
t0 = time.time()
rows = list(csv.reader(lines))
t1 = time.time()
with open('airports.csv.out', 'wb') as file_out:
writer = csv.writer(file_out)
writer.writerows(rows)
t2 = time.time()
print 'reading took %.3f seconds' % (t1 - t0)
print 'writing took %.3f seconds' % (t2 - t1)
print 'complete took %.3f seconds' % (t2 - t0)
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