[Tutor] str object is not callable

[Chris Hare]

This piece of code works:

Big-Mac:Classes chare$ more tmp.py
import re

def special_match(string, search=re.compile(r'[^a-zA-Z0-9\.\ \-\#\$\*\@\!\%\^\&]').search):
        #string = string.rstrip()
        return not bool(search(string))

print special_match("admin")
print special_match("&!*")
print special_match("=")

Big-Mac:Classes chare$ python tmp.py
True
True
False
Big-Mac:Classes chare$ 

However, when I use the EXACT same code in the context of the larger code, I get the error

    return not bool(search(strg))
TypeError: 'str' object is not callable

The input to the function in the larger program is the same as the first test in the small script that works -- "admin".  

As a side note -- the rstrip call is also broken, although the string module is imported.  I just can't figure out why this code works in one context and not in another.