This script will put commas between each group of three digits number. For example, 1234567 will become 1,234,567.
import re
putComma = lambda x: (",".join(re.findall("\d{1,3}", \
str(x)[::-1])))[::-1]
print putComma(1234567) # 1,234,567
print putComma(12345678) # 12,345,678
print putComma(123456789) # 123,456,789
print putComma(1212) # 1,212
