How to check if a string is empty in python?
Steven D'Aprano
steve at REMOVE.THIS.cybersource.com.au
Wed May 2 18:50:37 EDT 2007
On Wed, 02 May 2007 13:35:47 -0700, noagbodjivictor wrote:
> How to check if a string is empty in python?
> if(s == "") ??
In no particular order, all of these methods will work:
# test s is equal to another empty string
if s == "":
# assuming s is a string, test that it is empty
if not s:
# test s is a string and it is empty
if isinstance(s, str) and not s:
# test s has length 0
if len(s) == 0:
# test the length of s evaluates as false
if not len(s):
# a long way to test the length of s
if s.__len__() < 1:
# a stupid way to test s is empty
if bool(s) == False:
# a REALLY stupid way to test s is empty
if (bool(s) == False) == True:
# test that appending s to itself is itself
if s+s == s:
# test that s has none of any character
if not filter(None, [1 + s.find(chr(n)) for n in range(256)]):
That last one is really only good for wasting CPU cycles.
--
Steven.
More information about the Python-list
mailing list