22 Useful Python Code Examples: Become a Python Pro

22 Useful Python Code Examples: Become a Python Pro

Python is one of the most popular programming languages known for its versatility and usefulness in solving everyday tasks. In this article, we will briefly discuss 22 useful code examples that harness the power of Python. Some of these examples may be familiar to you, while others may be new and interesting. All of these examples are easy to remember and can enhance your Python skills. So, let's dive in!

1. Getting Vowels
   This example returns the vowels "a e i o u" found in a string. It can be useful for searching or detecting vowels.

def get_vowels(string):  
    return [each for each in string if each in "aeiou"]  
  
get_vowels("animal")   ['a', 'i', 'a']  
get_vowels("sky")   []  
get_vowels("football")   ['o', 'o', 'a']  

2. Capitalizing the First Letter
   This example is used to capitalize the first letter of each word in a string. It works with strings containing one or more characters and can be useful for text analysis, data recording, and more.

def capitalize(string):  
    return string.title()  
  
capitalize("shop")   'Shop'  
capitalize("python programming")   'Python Programming'  
capitalize("how are you!")   'How Are You!'  

3. Printing a String N Times
   This example can print any given string N times without using Python loops.

n = 5  
string = "Hello World "  
print(string * n)  
 Output: Hello World Hello World Hello World Hello World Hello World  

4. Merging Two Dictionaries
   This example merges two dictionaries into one.

def merge(dict1, dict2):  
    dict3 = dict1.copy()  
    dict3.update(dict2)  
    return dict3  
  
dict1 = {1: "hello", 2: "world"}  
dict2 = {3: "Python", 4: "Programming"}  
merge(dict1, dict2)  
 Output: {1: 'hello', 2: 'world', 3: 'Python', 4: 'Programming'}  

5. Calculating Execution Time
   This example is useful when you need to know the time taken to execute a program or function.

import time  
  
start_time = time.time()  
  
def fun():  
    a = 2  
    b = 3  
    c = a + b  
  
end_time = time.time()  
  
fun()  
timetaken = end_time - start_time  
print("Your program takes:", timetaken)  
 Output: Your program takes: 0.0345  

6. Swapping Variable Values
   This is a quick way to swap the values of two variables without using a third variable.

a = 3  
b = 4  
a, b = b, a  
print(a, b)  
 Output: a = 4, b = 3  

7. Checking for Duplicates
   This is the fastest way to check for duplicate values in a list.

def check_duplicate(lst):  
    return len(lst) != len(set(lst))  
  
check_duplicate([1, 2, 3, 4, 5, 4, 6])   True  
check_duplicate([1, 2, 3])   False  
check_duplicate([1, 2, 3, 4, 9])   False  

8. Filtering False Values
   This example is used to remove all false values from a list, such as False, 0, None, and "".

def filtering(lst):  
    return list(filter(None, lst))  
  
lst = [None, 1, 3, 0, "", 5, 7]  
filtering(lst)   [1, 3, 5, 7]  

9. Getting the Size in Bytes
   This example returns the length of a string in bytes, which is useful when you need to know the size of a string variable.

def byte_size(string):  
    return len(string.encode("utf8"))  
  
byte_size("Python")   6  
byte_size("Data")   4  

10. Memory Usage
    This example allows you to get the memory usage of any variable in Python.

import sys  
  
var1 = "Python"  
var2 = 100  
var3 = True  
  
print(sys.getsizeof(var1))   55  
print(sys.getsizeof(var2))   28  
print(sys.getsizeof(var3))   28  

11. Anagrams
    This code is useful for checking if a string is an anagram. An anagram is a word that is formed by rearranging the letters of another word.

from collections import Counter  
  
def anagrams(str1, str2):  
    return Counter(str1) == Counter(str2)  
  
anagrams("abc1", "1bac")   True  

12. Sorting a List
    This example sorts a list. Sorting is a common task that can be implemented with a loop, but you can speed up your work using the built-in sort method.

my_list = ["leaf", "cherry", "fish"]  
my_list1 = ["D", "C", "B", "A"]  
my_list2 = [1, 2, 3, 4, 5]  
  
my_list.sort()   ['cherry', 'fish', 'leaf']  
my_list1.sort()   ['A', 'B', 'C', 'D']  
print(sorted(my_list2, reverse=True))   [5, 4, 3, 2, 1]  

13. Sorting a Dictionary
    This example sorts a dictionary.

orders = {'pizza': 200, 'burger': 56, 'pepsi': 25, 'Coffee': 14}  
sorted_dic = sorted(orders.items(), key=lambda x: x[1])  
print(sorted_dic)  
 Output: [('Coffee', 14), ('pepsi', 25), ('burger', 56), ('pizza', 200)]  

14. Getting the Last Element of a List
    This example shows how to get the last element of a list.

my_list = ["Python", "JavaScript", "C++", "Java", "C", "Dart"]  
  
 Method 1  
print(my_list[-1])   Dart  
  
 Method 2  
print(my_list.pop())   Dart  

15. Converting a Comma-Separated List to a String
    This code converts a comma-separated list into a single string. It is useful when you need to concatenate the entire list with a string.

my_list1 = ["Python", "JavaScript", "C++"]  
my_list2 = ["Java", "Flutter", "Swift"]  
  
 Example 1  
print("My favourite Programming Languages are", ", ".join(my_list1))  
 Output: My favourite Programming Languages are Python, JavaScript, C++  
  
print(", ".join(my_list2))  
 Output: Java, Flutter, Swift  

16. Checking for Palindromes
    This example demonstrates how to quickly check for palindromes.

def palindrome(data):  
    return data == data[::-1]  
  
palindrome("level")   True  
palindrome("madaa")   False  

17. Shuffling a List
    This example shuffles a list.

from random import shuffle  
  
my_list1 = [1, 2, 3, 4, 5, 6]  
my_list2 = ["A", "B", "C", "D"]  
  
shuffle(my_list1)   [4, 6, 1, 3, 2, 5]  
shuffle(my_list2)   ['A', 'D', 'B', 'C']  

18. Converting a String to Upper and Lower Case
    This example converts a string to uppercase and lowercase.

str1 = "Python Programming"  
str2 = "I'm a PROGRAMMER"  
  
print(str1.upper())   PYTHON PROGRAMMING  
print(str2.lower())   i'm a programmer  

19. String Formatting
    This code allows you to format a string by appending data from variables. In Python, formatting means attaching data from variables to a string.

 Example 1  
str1 = "Python Programming"  
str2 = "I'm a {}".format(str1)  
 Output: I'm a Python Programming  
  
 Example 2 - another way  
str1 = "Python Programming"  
str2 = f"I'm a {str1}"  
 Output: I'm a Python Programming  

20. Finding Substrings
    This example will be useful for finding substrings in a string. I will implement it in two ways to avoid writing too much code.

programmers = [  
    "I'm an expert Python Programmer",  
    "I'm an expert Javascript Programmer",  
    "I'm a professional Python Programmer",  
    "I'm a beginner C++ Programmer"  
]  
  
 Method 1  
for p in programmers:  
    if p.find("Python"):  
        print(p)  
  
 Method 2  
for p in programmers:  
    if "Python" in p:  
        print(p)  

21. Printing in One Line
    We know that the print function prints each item on a new line. However, if you want to print in the same line without