String concatenation comparison Also see: - http://greaterdebater.com/blog/gabe/post/7 - http://www.skymind.com/~ocrow/python_string/

stest.py

#!/usr/bin/env python
"""
String concatenation comparison

Also see:

- http://greaterdebater.com/blog/gabe/post/7
- http://www.skymind.com/~ocrow/python_string/
"""
# Standard library
import commands
import locale
import os
from sys import argv
import timeit


def method1():
    out_str = ""
    for num in xrange(loops):
        out_str += repr(num)
    ps_stats()
    return out_str


def method2():
    from UserString import MutableString
    out_str = MutableString()
    for num in xrange(loops):
        out_str += repr(num)
    ps_stats()
    return out_str


def method3():
    from array import array
    char_array = array("c")
    for num in xrange(loops):
        char_array.fromstring(repr(num))
    out_str = char_array.fromstring(repr(num))
    ps_stats()
    return out_str


def method4():
    str_list = []
    for num in xrange(loops):
        str_list.append(repr(num))
    out_str = "".join(str_list)
    ps_stats()
    return out_str


def method5():
    from cStringIO import StringIO
    file_str = StringIO()
    for num in xrange(loops):
        file_str.write(repr(num))
    ps_stats()
    return file_str.getvalue()


def method6():
    out_str = "".join([repr(num) for num in xrange(loops)])
    ps_stats()
    return out_str


def method7():
    out_str = ""
    for num in xrange(loops):
        out_str = "%s%s" % (out_str, num)
    ps_stats()
    return out_str


def ps_stats():
    global process_size
    ps = commands.getoutput("ps -o rss -p %s" % pid)
    process_size = ps.split()[1]


def call_method(num):
    global process_size
    method = "method%s" % str(num)
    time = timeit.timeit("%s()" % method,
                         setup="from __main__ import %s" % method,
                         number=1)

    print "method%s, %6.3f seconds, %7s KB" % (num, time, process_size)

locale.setlocale(locale.LC_ALL, 'en_US')
process_size = ""
try:
    loops = int(argv[1])
except:
    loops = 1000000
pid = os.getpid()

print "Loops: %s\n" % locale.format("%d", loops, grouping=True)
for i in xrange(1, 8):
    if i in (2, 7) and loops >= 100000:
        continue
    call_method(i)