Question

How to change file extension in Python?

Answer 1

The open on the source file is unnecessary, since os.rename only needs the source and destination paths to get the job done. Moreover, os.rename always returns None, so it doesn't make sense to call open on its return value.

import os,sys

folder = 'E:/.../1936342-G/test'

for filename in os.listdir(folder):

infilename = os.path.join(folder,filename)

if not os.path.isfile(infilename): continue

oldbase = os.path.splitext(filename)

newname = infilename.replace('.grf', '.las')

output = os.rename(infilename, newname)

I simply removed the two open. Check if this works for you.

Answer 2

Python don't have a file extension....