Python: NameError: free variable 're' referenced before assignment in enclosing scope

Most likely, you are assigning to re (presumably inadvertently) at some point below line 561, but in the same function. This reproduces your error:

import re

def main():
    term = re.compile("foo")
    re = 0

main()

"free variable" in the traceback suggests that this is a local variable in an enclosing scope. something like this:

 baz = 5

 def foo():
     def bar():
         return baz + 1

     if False:
          baz = 4

     return bar()

so that the baz is referring to a local variable (the one who's value is 4), not the (presumably also existing) global. To fix it, force baz to a global:

 def foo():
     def bar():
         global baz
         return baz + 1

so that it won't try to resolve the name to the nonlocal version of baz. Better yet, find where you're using re in a way that looks like a local variable (generator expressions/list comprehensions are a good place to check) and name it something else.