Timing the search for a string in a list.

stringinlist.py

#!/usr/bin/env python

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301, USA.
#

import re
import timeit

my_list = ['abc-123', 'def-456', 'ghi-789', 'abc456', 'abc', 'abd']
re_abc = re.compile("^abc$")


def re_check():
    """compiles a regular expression and checks for matches"""
    return [i for i in my_list if re.match('^abc$', i)]


def simple_check():
    """AFAIK only works for ascii strings in Python < 3.0"""
    return [i for i in my_list if i == 'abc']


def re_precompiled():
    """uses precompiled regular expression and checks for matches"""
    return [i for i in my_list if re_abc.match(i)]


def contains_check():
    """looks for existing entry in my_list. returns only one element"""
    return ["abc"] if "abc" in my_list else []


def count_check():
    """looks for existing entry in my_list. returns all elements"""
    return ["abc"]*my_list.count("abc")


if __name__ == "__main__":
    # running checks
    for check in [i for i in dir() \
            if "<type 'function'>" == str(type(eval(i)))]:
        t = eval("timeit.Timer(%s)" % check)
        print '%s result >>' % check, eval("%s()" % check)
        print "%.2f usec/pass" % (1000000 * t.timeit(number=100000) / 100000)


# Results:
# ==================================
#~ contains_check result >> ['abc']
#~ 0.42 usec/pass
#~ count_check result >> ['abc']
#~ 0.74 usec/pass
#~ re_check result >> ['abc']
#~ 12.43 usec/pass
#~ re_precompiled result >> ['abc']
#~ 4.47 usec/pass
#~ simple_check result >> ['abc']
#~ 0.86 usec/pass