comparison of two functions which map the frequency of identical adjacent characters

output.txt

Python 3.6.0 (v3.6.0:41df79263a11, Dec 23 2016, 07:18:10) [MSC v.1900 32 bit (Intel)] on win32
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>>> import timeit, itertools, random, string, statistics
>>> 
>>> def summarize(s):
    return ''.join(str(sum(1 for _ in i[1])) + i[0] for i in itertools.groupby(s))

>>> def freq_map(s):
	num = 0			# number of adjacent, identical characters
	curr = s[0]		# current character being processed
	result = ''		# result of function

	for i in range(len(s)):
		if s[i] == curr:
			num += 1
		else:
			result += str(num) + curr
			curr = s[i]
			num = 1

	result += str(num) + curr

	return result

>>> stimes, ftimes = [],[]
>>> for i in range(5):
	s = ''.join(random.choices(string.ascii_uppercase + string.digits, k=20))
	stimes.append(timeit.timeit("[summarize('{0}')]".format(s), globals=globals()))
	ftimes.append(timeit.timeit("[freq_map('{0}')]".format(s), globals=globals()))

	
>>> stimes
[20.988593877864446, 22.52263322176168, 20.372410243008744, 24.40531525133622, 22.33915113723708]
>>> ftimes
[12.049683384776813, 10.223272452521542, 13.329730250382795, 16.72326475475097, 11.291220080838343]
>>> statistics.mean(stimes)
22.125620746241633
>>> statistics.mean(ftimes)
12.723434184654092
>>> 12.723434184654092 / 22.125620746241633
0.5750543377100666