Validating a Filename

From IronPython Cookbook

Generating a filename or getting one from User Input can lead to invalid characters slipping in. Luckily the .Net Framework has a method that returns invalid characters for the current platform which can be used to clean up the filename.

The function (MSDN Docs) returns a list of Chars which need to be converted to strings for use in IronPython. In this example, the characters are just removed from the string.

import System.IO 
test = r"bad:filename\goesgood?"
 
for c in System.IO.Path.GetInvalidFileNameChars():
   test = test.replace(c.ToString(), '')

print test

Outputs:

badfilenamegoesgood

The same as a one-liner:

test = ''.join(c for c in test if c not in System.IO.Path.GetInvalidFileNameChars())

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