python library not defined in user defined function

[johnEmScott]

Why doesn't this work?

def main():
    import os
    fileName = "text.txt"
    userfunction(fileName)

def userfunction(fileName):
    os.path.exists(fileName)

main()

I get the following error:

Error:
NameError: name 'os' is not defined

[ndc85430]

Because the import is local to your main function. Imports should go at the top of the file, as per PEP 8.

[DT2000]

As mentioned above by ndc85430 you need to import your modules before the actual code functions are executed.

import os

def main():
    fileName = "text.txt"
    userfunction(fileName)

def userfunction(fileName):
    os.path.exists(fileName)

main()