perf_counter()-start giving weird result Question: I was building my own version of the timeit function, which returns the amount of time it takes to run a function n times. However, when I ran it with a sample input, I received the following output, which doesn’t seem right, as it ran very quickly. 9.400071576237679e-06 My code: …
%%timeit magic command and variable set to global in function Question: Here is a MRE: %%timeit variable = 0 def func(): global variable variable += 1 func() assert (variable == 1) It works perfectly without the magic command %%timeit. I’m not sure I understand why it doesn’t work when I add the magic command. It …
Best method to measure execution time of a python snippet Question: I want to compare execution time of two snippets and see which one is faster. So, I want an accurate method to measure execution time of my python snippets. I already tried using time.time(), time.process_time(), time.perf_counter_ns() as well as timeit.timeit(), but I am facing …
Sorting rows by the number of list elements the row contains Question: Taking as example the following table: index column_1 column_2 0 bli bli d e 1 bla bla a b c d e 2 ble ble a b c If I give a token_list = [‘c’, ‘e’] I want to order the table by …
timeit and its default_timer completely disagree Question: I benchmarked these two functions (they unzip pairs back into source lists, came from here): n = 10**7 a = list(range(n)) b = list(range(n)) pairs = list(zip(a, b)) def f1(a, b, pairs): a[:], b[:] = zip(*pairs) def f2(a, b, pairs): for i, (a[i], b[i]) in enumerate(pairs): pass Results …
Getting "TypeError: 'module' is not callable" when calculating execution time with timeit Question: I am trying to calculate the timings of my python code but I keep getting: TypeError – ‘module’ is not callable import timeit timeit.timeit(‘”-“.join(str(n) for n in range(100))’, number=10000) The link I am checking is this – https://docs.python.org/2/library/timeit.html I would expect to …
IPython %timeit what is loop and iteration in the options? Question: I am wondering about the %timeit command in IPython From the docs: %timeit [-n<N> -r<R> [-t|-c] -q -p<P> -o] setup_code Options: -n: execute the given statement times in a loop. If this value is not given, a fitting value is chosen. -r: repeat the …
When should I ever use file.read() or file.readlines()? Question: I noticed that if I iterate over a file that I opened, it is much faster to iterate over it without “read”-ing it. i.e. l = open(‘file’,’r’) for line in l: pass (or code) is much faster than l = open(‘file’,’r’) for line in l.read() / …
What unit of time does timeit return? Question: I don’t know how to interpret the output from Python’s timeit.timeit() function. My code is as follows: import timeit setup = “”” import pydash list_of_objs = [ {}, {‘a’: 1, ‘b’: 2, 0: 0}, {‘a’: 1, ‘c’: 1, ‘p’: lambda x: x} ] “”” print(timeit.timeit(“pydash.filter_(list_of_objs, {‘a’: 1})”, …
What is %timeit in Python? Question: I always read the code to calculate the time like this way: %timeit function() What does "%" mean here? I think, the "%" is always used to replace something in a string, like %s means replace a string, %d replace a data, but I have no idea about this …
