John Machin wrote: > On Apr 6, 9:25 am, Mark Dickinson <[EMAIL PROTECTED]> wrote: >> On Apr 5, 6:19 pm, [EMAIL PROTECTED] wrote: >> >>> which is the best way to check if a string is an number or a char? >>> could the 2nd example be very expensive timewise if i have to check a >>> lot of strings? >> You might be interested in str.isdigit: >> >>>>> print str.isdigit.__doc__ >> S.isdigit() -> bool >> >> Return True if all characters in S are digits >> and there is at least one character in S, False otherwise. >> > > This doesn't cater for negative integers. > No, it doesn't, but
s.isdigit() or (s[0] in "+-" and s[1:].isdigit) # untested does. and *may* be quicker than other examples. Not that speed is usually a concern in validation routines anyway ... regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
