Skip to content

@zed /profile_select_random_element.py
Created

Embed URL

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
"""Measure relative performance of answers to [1].
[1] http://stackoverflow.com/questions/1456617
"""
import linecache
import random
from timeit import default_timer
WORDS_FILENAME = "/etc/dictionaries-common/words"
def measure(func):
measure.func_to_measure.append(func)
return func
measure.func_to_measure = []
@measure
def dcrosta():
words = [line.strip() for line in open(WORDS_FILENAME)]
return random.choice(words)
@measure
def dcrosta_no_strip():
words = [line for line in open(WORDS_FILENAME)]
return random.choice(words)
def select_random_line(filename):
selection = None
count = 0
for line in file(filename, "r"):
if random.randint(0, count) == 0:
selection = line.strip()
count = count + 1
return selection
@measure
def mark_ransom():
return select_random_line(WORDS_FILENAME)
def select_random_line_no_strip(filename):
selection = None
count = 0
for line in file(filename, "r"):
if random.randint(0, count) == 0:
selection = line
count = count + 1
return selection
@measure
def mark_ransom_no_strip():
return select_random_line_no_strip(WORDS_FILENAME)
def choose_from(iterable):
"""Choose a random element from a finite `iterable`.
If `iterable` is a sequence then use `random.choice()` for efficiency.
Return tuple (random element, total number of elements)
"""
selection, i = None, None
for i, item in enumerate(iterable):
if random.randint(0, i) == 0:
selection = item
return selection, (i+1 if i is not None else 0)
@measure
def mark_ransom_choose_from():
return choose_from(open(WORDS_FILENAME))
@measure
def nadia():
global total_num_lines
total_num_lines = sum(1 for _ in open(WORDS_FILENAME))
line_number = random.randint(0, total_num_lines)
return linecache.getline(WORDS_FILENAME, line_number)
@measure
def nadia_known_num_lines():
line_number = random.randint(0, total_num_lines)
return linecache.getline(WORDS_FILENAME, line_number)
@measure
def jfs():
return random.choice(list(open(WORDS_FILENAME)))
def timef(func, number=1000, timer=default_timer):
"""Return number of seconds it takes to execute `func()`."""
start = timer()
for _ in range(number):
func()
return (timer() - start) / number
def main():
# measure time
times = dict((f.__name__, timef(f, number=10))
for f in measure.func_to_measure)
# print from fastest to slowest
maxname_len = max(map(len, times))
last = None
for name in sorted(times, key=times.__getitem__):
print "%s %4.2g seconds %.2f" % (name.ljust(maxname_len), times[name],
last and times[name] / last or 1)
last = times[name]
if __name__ == "__main__":
main()
# nadia_known_num_lines 9.6e-06 seconds 1.00
# nadia 0.056 seconds 5843.51
# jfs 0.062 seconds 1.10
# dcrosta_no_strip 0.091 seconds 1.48
# dcrosta 0.13 seconds 1.41
# mark_ransom_no_strip 0.66 seconds 5.10
# mark_ransom_choose_from 0.67 seconds 1.02
# mark_ransom 0.69 seconds 1.04
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Something went wrong with that request. Please try again.