tips-to-decrease-executionTime-in-python

Here are some amazingly useful tips to decrease execution time in python programs

As a beginner I admit that most of the tips given below are some of my deeds too, so this repo we will learn how to decrease the execution time.

The method I used here to calculate the time is previously explained in one of my repos which you can find by
clicking here

points to be noted beforehand

• The execution-time for every code given below is based on multiple runs and optimal one of all.
• Check out the other files in this repo for hands-on trial.
• Time may vary device to device.

do not import the whole module

When we try to use certain module and we know it's sole purpose is only to serve a single function. Then try importing only that single function instead of the whole thing.

syntax

from module_name import function_name1, function_name2,etc,...

Example:

from math import ceil, floor

i = 9.67

print(ceil(i))
print(floor(i))

output:
  10
  9

Execution time: 0.008982419967651367

import math

i = 9.67

print(math.ceil(i))
print(math.floor(i))

Execution time: 0.01605224609375 see the difference, amazing right

no temp variables

In one of my previous repos about different swapping techniques I stated to use

a = 10
b = 20
a, b = b, a
print(a,b)

Execution time is : 0.014656782150268555

Instead of the below code

x = 10
y = 20
temp = x
x = y
y = temp
print(x,y)

Output: 20 10

Execution time is : 0.014772176742553711 Might be closer but worthwhile when running in a loop.

for loop for the win

This is the most common mistake made by most of us, that is using while-loop even tho the job could be done with a for-loop.

using for-loop

for i in range(10):
print(i)
if i == 9:
    print('over')
    
output:
0
1
2
3
4
5
6
7
8
9
over

Execution time is : 0.05827617645263672

using while-loop

i=0
while True:
    print(i)
    i += 1
    if i == 10:
        print('over')
        break
        
output:
0
1
2
3
4
5
6
7
8
9
over

Execution time is : 0.07421302795410156

The old saying goes Little efforts can make a huge impact.

As a programmer I say Every bit counts ;)