# documentation is at http://www.outwardlynormal.com/python/swapextensions.htm
# send in 3 strings: directory path, "before" extension, "after" extension
import os
def swapextensions(dir, before, after):
if before[:1]!='.': before = '.'+before
if after[:1]!='.': after = '.'+after
os.path.walk(dir, callback, (before, -len(before), after))
def callback((before, thelen, after), dir, files):
for oldname in files:
if oldname[thelen:]==before:
oldfile = os.path.join(dir, oldname)
newfile = oldfile[:thelen] + after
os.rename(oldfile, newfile)
if __name__=='__main__':
import sys
if len(sys.argv) != 4:
print "Usage: swapext rootdir before after"
sys.exit(100)
swapextensions(sys.argv[1], sys.argv[2], sys.argv[3])
