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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def col (loc,strg):
 """Returns current column within a string, counting newlines as line separators. The first column is number 1. Note: the default parsing behavior is to expand tabs in the input string before starting the parsing process. See L{I{ParserElement.parseString}<ParserElement.parseString>} for more information on parsing strings containing C{<TAB>}s, and suggested methods to maintain a consistent view of the parsed string, the parse location, and line and column positions within the parsed string. """

    s = strg
    return 1 if loc<len(s) and s[loc] == '\n' else loc - s.rfind("\n", 0, loc)