Quickly time your loops with a single line of code. Take code like this

for i in arr:
  # do something

and time it like this

from looptimer import timing
for i in timing(arr):
  # do something

Example

arr = range(10)
for i in timing(arr):
  time.sleep(1)

Iteration 0 took 1.0011s
Iteration 1 took 1.0011s
Iteration 2 took 1.0011s
Iteration 3 took 1.0008s
Iteration 4 took 1.0008s
Total runtime: 5.0068s
Average runtime per loop: 1.0010s
Shortest loop: 1.0008s
Longest loop: 1.0011s

Print every N iterations using the every_n parameter.

arr = range(5)
for i in timing(arr, every_n=2): # prints every 2 iterations
    time.sleep(1)

Print every % of your way through the data using the every_fraction parameter.

arr = range(5)
for i in timing(arr, every_fraction=0.5): # prints every 50% of the way through the data
    time.sleep(1)

Credits

Logo courtesy of Launchaco: GitHub