Timing While and For Loops in Python

# conclusion: while loop is slower than for loop

def while1():
    x = 0
    while x < 100:
        x += 1
    return x

print while1()  # test

def for1():
    x = 0
    for y in range(100):
        x += 1
    return x

print for1()

# using xrange()
def for2():
    x = 0
    for y in xrange(100):
        x += 1
    return x

print for2()

import timeit

print "Timing 100000 passes ..."

t = timeit.Timer('while1()', "from __main__ import while1")
elapsed = (10 * t.timeit(number=100000))
print "Function while1() takes %0.3f microseconds/pass" % elapsed

t = timeit.Timer('for1()', "from __main__ import for1")
elapsed = (10 * t.timeit(number=100000))
print "Function for1() takes %0.3f microseconds/pass" % elapsed

t = timeit.Timer('for2()', "from __main__ import for2")
elapsed = (10 * t.timeit(number=100000))
print "Function for2() takes %0.3f microseconds/pass" % elapsed

"""
typical result:
Function while1() takes 24.712 microseconds/pass
Function for1() takes 22.281 microseconds/pass
Function for2() takes 20.341 microseconds/pass
"""