22 Useful Python Code Examples: From Vowels to Robotics

22 Useful Python Code Examples: From Vowels to Robotics

Python is one of the most popular programming languages, known for its versatility and usefulness in everyday tasks. In this article, we will explore 22 useful code examples that harness the power of Python. Some of these examples may be familiar to you, while others will be new and interesting. All of these examples are easy to remember and implement in your own projects.

1. Finding Vowels

This code example returns the vowels found in a given string. It can be useful for searching or detecting vowels.

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

2. Capitalizing the First Letter

This example capitalizes the first letter of each word in a string. It can be useful for text analysis, data recording, and more.

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

3. Printing a String N Times

This code example prints a given string N times without using loops in Python.

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(dic1, dic2):  
    dic3 = dic1.copy()  
    dic3.update(dic2)  
    return dic3  
  
dic1 = {1: "hello", 2: "world"}  
dic2 = {3: "Python", 4: "Programming"}  
print(merge(dic1, dic2))  
 Output: {1: 'hello', 2: 'world', 3: 'Python', 4: 'Programming'}  

5. Calculating Execution Time

This example is useful when you need to know how much time it takes 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 code provides 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))  
  
print(check_duplicate([1, 2, 3, 4, 5, 4, 6]))   True  
print(check_duplicate([1, 2, 3]))   False  
print(check_duplicate([1, 2, 3, 4, 9]))   False  

8. Filtering False Values

This example filters out 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]  
print(filtering(lst))  
 Output: [1, 3, 5, 7]  

9. Size in Bytes

This code 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"))  
  
print(byte_size("Python"))   6  
print(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 formed by rearranging the letters of another word.

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

12. Sorting a List

This example sorts a list. Sorting is a commonly used task that can be implemented with a few lines of code using the built-in sorting 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 based on its values.

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 code demonstrates two ways 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 combine 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++  
  
 Example 2  
print(", ".join(my_list2))  
 Output: Java, Flutter, Swift  

16. Checking for Palindromes

This example quickly checks for the presence of palindromes.

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

17. Shuffling a List

This code shuffles a list using the shuffle function from the random module.

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 String Case

This example converts a string to uppercase and lowercase.

str1 = "Python Programming"  
str2 = "IM A PROGRAMMER"  
  
print(str1.upper())   'PYTHON PROGRAMMING'  
print(str2.lower())   'im a programmer'  

19. String Formatting

This code allows you to format a string by concatenating variables.

 Example 1  
str1 = "Python Programming"  
str2 = "I'm a {}".format(str1)  
print(str2)   "I'm a Python Programming"  
  
 Example 2 (using f-strings)  
str1 = "Python Programming"  
str2 = f"I'm a {str1}"  
print(str2)   "I'm a Python Programming"  

20. Substring Search

This example will be useful for searching for substrings in a string. It demonstrates two methods that avoid writing a lot of 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 on the Same Line

This code shows how to print