While learning programming and reading some resources you’d have come across this word ‘abstraction’ which simply means to reduce and reuse the code as much as possible.
Functions and Modules facilitate abstraction. You create functions when you want to do something repeatedly within a file.
Modules come into picture when you want to reuse a group of functions in different source files. Modules are also useful in structuring the program well.
- Using Standard Libraries and other third party modules:
- Structuring the program
Using Standard Libraries
Example: You can read about the methods/functions of all the standard libraries in the official Python Docs in detail.
import time for i in range(100): time.sleep(1) # Waits for 1 second and then executes the next command print(str(i) + ' seconds have passed') # prints the number of seconds passed after the program was started
# To calculate the execution time of a part of program import time start = time.time() # code here end = time.time() print('Execution time:' , end-start)
# Using math Module import math print(math.sqrt(100)) # prints 10
Using third party Modules
# To make http requests import requests rq = requests.get(target_url) print(rq.status_code)
Find out more about python-requests module here
To structure programs
We want to make a program that has various functions regarding prime numbers. So lets start. We will define all the functions in
# prime_functions.py from math import ceil, sqrt def isPrime(a): if a == 2: return True elif a % 2 == 0: return False else: for i in range(3,ceil(sqrt(a)) + 1,2): if a % i == 0: return False return True def print_n_primes(a): i = 0 m = 2 while True: if isPrime(m) ==True: print(m) i += 1 m += 1 if i == a: break
Now we want to use the functions that we just created in
prime_functions.py so we create a new file
playground.py to use those functions.
Please note that this program is far too simple to make two separate files, it is just to demonstrate. But when there are large complex programs, making different files is really useful.
# playground.py import prime_functions print(prime_functions.isPrime(29)) # returns True