StrNumberCommaInsert.py

def StrNumberCommaInsert(s):
    if s.replace('.', '').isdigit():
        p = 0
        if '.' in s:
            p = len(s) - (s.index('.') + 1)
        try:
            n = int(s)
        except ValueError:
            n = float(s)
        return ("{:,.%sf}" % p).format(n)