Python str concat benchmark

python-str-concat-benchmark.py

#!/usr/bin/env python

"""
Python str concat benchmark

Copyright (C) 2013-2020 by Denis Ryzhkov <[email protected]>
MIT License, see http://opensource.org/licenses/MIT
"""

from time import time
import sys

is_py3 = sys.version_info.major == 3
if is_py3:
    xrange = range

a = "hello"
b = "world"
loops = 10 ** 6
results = []

start = time()
for _ in xrange(loops):
    result = ",".join((a, b))
results.append(("join", time() - start))

start = time()
for _ in xrange(loops):
    result = a + "," + b
results.append(("+", time() - start))

start = time()
for _ in xrange(loops):
    result = "%s,%s" % (a, b)
results.append(("%", time() - start))

start = time()
for _ in xrange(loops):
    result = "{},{}".format(a, b)
results.append(("format", time() - start))

if is_py3:  # Else comment-out: f-strings are not supported in py2
    start = time()
    for _ in xrange(loops):
        result = f"{a},{b}"
    results.append(("f-string", time() - start))

for name, value in sorted(results, key=lambda row: row[1]):
    print("{:>10} {:7.6}".format(name, value))


"""
Results:


# 2013-02-27, python-2.?

         + 0.977680
      join 1.388858
         % 1.507211
    format 1.986074


# 2020-06-08, python-2.7.17

         + 0.097954
      join 0.152078
         % 0.165025
    format 0.210494


# 2020-06-08, python-3.8.2

  f-string 0.158507
         + 0.192736
      join 0.208459
         % 0.273779
    format 0.367376
"""