Tutorial Playlist
200 Lessons1. Introduction to Python
2. Features of Python
3. How to install python in windows
4. How to Install Python on macOS
5. Install Python on Linux
6. Hello World Program in Python
7. Python Variables
8. Global Variable in Python
9. Python Keywords and Identifiers
10. Assert Keyword in Python
11. Comments in Python
12. Escape Sequence in Python
13. Print In Python
14. Python-if-else-statement
15. Python for Loop
16. Nested for loop in Python
17. While Loop in Python
18. Python’s do-while Loop
19. Break in Python
20. Break Pass and Continue Statement in Python
21. Python Try Except
22. Data Types in Python
23. Float in Python
24. String Methods Python
25. List in Python
26. List Methods in Python
27. Tuples in Python
28. Dictionary in Python
29. Set in Python
30. Operators in Python
31. Boolean Operators in Python
32. Arithmetic Operators in Python
33. Assignment Operator in Python
34. Bitwise operators in Python
35. Identity Operator in Python
36. Operator Precedence in Python
37. Functions in Python
38. Lambda and Anonymous Function in Python
39. Range Function in Python
40. len() Function in Python
41. How to Use Lambda Functions in Python?
42. Random Function in Python
43. Python __init__() Function
44. String Split function in Python
45. Round function in Python
46. Find Function in Python
47. How to Call a Function in Python?
48. Python Functions Scope
49. Method Overloading in Python
50. Method Overriding in Python
51. Static Method in Python
52. Python List Index Method
53. Python Modules
54. Math Module in Python
55. Module and Package in Python
56. OS module in Python
57. Python Packages
58. OOPs Concepts in Python
59. Class in Python
60. Abstract Class in Python
61. Object in Python
62. Constructor in Python
63. Inheritance in Python
64. Multiple Inheritance in Python
65. Encapsulation in Python
66. Data Abstraction in Python
67. Opening and closing files in Python
68. How to open JSON file in Python
69. Read CSV Files in Python
70. How to Read a File in Python
71. How to Open a File in Python?
72. Python Write to File
73. JSON Python
74. Python JSON – How to Convert a String to JSON
75. Python JSON Encoding and Decoding
76. Exception Handling in Python
77. Recursion in Python
78. Python Decorators
79. Python Threading
80. Multithreading in Python
81. Multiprocеssing in Python
82. Python Regular Expressions
83. Enumerate() in Python
84. Map in Python
85. Filter in Python
86. Eval in Python
87. Difference Between List, Tuple, Set, and Dictionary in Python
88. List to String in Python
89. Linked List in Python
90. Length of list in Python
91. Reverse a List in Python
92. Python List remove() Method
93. How to Add Elements in a List in Python
94. How to Reverse a List in Python?
95. Difference Between List and Tuple in Python
96. List Slicing in Python
97. Sort in Python
98. Merge Sort in Python
99. Selection Sort in Python
100. Sort Array in Python
101. Sort Dictionary by Value in Python
102. Datetime Python
103. Random Number in Python
104. 2D Array in Python
105. Abs in Python
106. Advantages of Python
107. Anagram Program in Python
108. Append in Python
109. Applications of Python
110. Armstrong Number in Python
111. Assert in Python
112. Binary Search in Python
113. Binary to Decimal in Python
114. Bool in Python
115. Calculator Program in Python
116. chr in Python
117. Control Flow Statements in Python
118. Convert String to Datetime Python
119. Count in python
120. Counter in Python
121. Data Visualization in Python
122. Datetime in Python
123. Extend in Python
124. F-string in Python
125. Fibonacci Series in Python
126. Format in Python
127. GCD of Two Numbers in Python
128. How to Become a Python Developer
129. How to Run Python Program
130. In Which Year Was the Python Language Developed?
131. Indentation in Python
132. Index in Python
133. Interface in Python
134. Is Python Case Sensitive?
135. Isalpha in Python
136. Isinstance() in Python
137. Iterator in Python
138. Join in Python
139. Leap Year Program in Python
140. Lexicographical Order in Python
141. Literals in Python
142. Matplotlib
143. Matrix Multiplication in Python
144. Memory Management in Python
145. Modulus in Python
146. Mutable and Immutable in Python
147. Namespace and Scope in Python
148. OpenCV Python
149. Operator Overloading in Python
150. ord in Python
151. Palindrome in Python
152. Pass in Python
153. Pattern Program in Python
154. Perfect Number in Python
155. Permutation and Combination in Python
156. Prime Number Program in Python
157. Python Arrays
158. Python Automation Projects Ideas
159. Python Frameworks
160. Python Graphical User Interface GUI
161. Python IDE
162. Python input and output
163. Python Installation on Windows
164. Python Object-Oriented Programming
165. Python PIP
166. Python Seaborn
167. Python Slicing
168. type() function in Python
169. Queue in Python
170. Replace in Python
171. Reverse a Number in Python
172. Reverse a string in Python
Now Reading
173. Reverse String in Python
174. Stack in Python
175. scikit-learn
176. Selenium with Python
177. Self in Python
178. Sleep in Python
179. Speech Recognition in Python
180. Split in Python
181. Square Root in Python
182. String Comparison in Python
183. String Formatting in Python
184. String Slicing in Python
185. Strip in Python
186. Subprocess in Python
187. Substring in Python
188. Sum of Digits of a Number in Python
189. Sum of n Natural Numbers in Python
190. Sum of Prime Numbers in Python
191. Switch Case in Python
192. Python Program to Transpose a Matrix
193. Type Casting in Python
194. What are Lists in Python?
195. Ways to Define a Block of Code
196. What is Pygame
197. Why Python is Interpreted Language?
198. XOR in Python
199. Yield in Python
200. Zip in Python
Manipulating strings is a fundamental skill in programming. In Python, one common string operation is reversing the string. This tutorial will discuss various methods to reverse a string in Python. We will cover methods using built-in functions, slicing, and also a method without using any built-in function.
Reversing a string refers to the arrangements of its characters in the opposite order. Python offers multiple ways to achieve this, each with its own advantages and drawbacks. This tutorial will detail the different methods to reverse a string in Python and give a comprehensive overview of the subject for those willing to learn programming.
Code:
def reverse_string(input_string):
reversed_string = ""
for char in input_string:
reversed_string = char + reversed_string
return reversed_string
original_string = "Hello, World!"
reversed_result = reverse_string(original_string)
print("Original:", original_string)
print("Reversed:", reversed_result)
Explanation:
Code:
def reverse_string_recursive(input_string):
if len(input_string) == 0:
return input_string
else:
return reverse_string_recursive(input_string[1:]) + input_string[0]
original_string = "Hello, World!"
reversed_result = reverse_string_recursive(original_string)
print("Original:", original_string)
print("Reversed:", reversed_result)
Explanation:
In this code:
Code:
def reverse_string_with_stack(input_string):
stack = [] # Initialize an empty stack
for char in input_string:
stack.append(char) # Push each character onto the stack
reversed_string = ""
while stack:
reversed_string += stack.pop() # Pop characters from the stack and build the reversed string
return reversed_string
original_string = "Hello, World!"
reversed_result = reverse_string_with_stack(original_string)
print("Original:", original_string)
print("Reversed:", reversed_result)
Explanation:
In this code:
Code:
def reverse_string_with_slice(input_string):
reversed_string = input_string[::-1] # Using extended slice notation
return reversed_string
original_string = "Hello, World!"
reversed_result = reverse_string_with_slice(original_string)
print("Original:", original_string)
print("Reversed:", reversed_result)
Explanation:
In this code:
In this code:
Code:
def reverse_string_with_list_comprehension(input_string):
reversed_string = ''.join([char for char in reversed(input_string)])
return reversed_string
original_string = "Hello, World!"
reversed_result = reverse_string_with_list_comprehension(original_string)
print("Original:", original_string)
print("Reversed:", reversed_result)
Explanation:
In this code:
Code:
def reverse_string(input_string):
reversed_string = ''.join(reversed(input_string))
return reversed_string
original_string = "Hello, World!"
reversed_result = reverse_string(original_string)
print("Original:", original_string)
print("Reversed:", reversed_result)
Explanation:
In this code:
In this code:
Code:
def reverse_string_with_slice(input_string):
reversed_string = input_string[::-1]
return reversed_string
original_string = "Hello, World!"
reversed_result = reverse_string_with_slice(original_string)
print("Original:", original_string)
print("Reversed:", reversed_result)
Explanation:
In this code:
Reversing a string in Python can be advantageous in various scenarios where you need to manipulate or analyze strings. Here are a few situations where reversing a string can be useful:
Overall, while reversing a string might not have a direct advantage in every situation, it's a fundamental string manipulation operation that can have various applications across different domains of programming and computer science.
The time complexity of reversing a string in Python depends on the method you use to perform the reversal. Let's analyze the time complexities of different methods:
This method has a time complexity of O(n), with n being the length of the input string. The slicing operation creates a new string with the characters in reversed order. The slicing operation takes linear time proportional to the length of the input string.
When using a loop to reverse a string, the time complexity is O(n). The loop iterates through each character once, and the string concatenation operation (reversed_string += char) takes O(1) time for each iteration. However, since this concatenation happens within the loop, the overall time complexity remains O(n).
This method also has a time complexity of O(n). The reversed() function returns an iterator that goes through the characters in reverse order. The join() operation takes O(n) time to concatenate the characters into a new string.
When using a stack to reverse a string, the time complexity is O(n). Pushing all characters onto the stack takes O(n) time, and popping them back to construct the reversed string also takes O(n) time.
Using recursion to reverse a string also has a time complexity of O(n). This is because the recursive function makes a recursive call for each character in the string, and each character is processed exactly once.
The time complexity of reversing a string using these common methods is generally O(n), where n is always the length of the input string. This is because you need to process each character in the string at least once to create the reversed version. However, the constant factors might differ between methods due to the different operations involved.
In this tutorial, we explored different ways to reverse a string in Python. From using slicing to creating custom functions without relying on inbuilt functions, we have examined various approaches. Understanding these methods is crucial as string manipulation is a common task in programming. Additionally, mastering string manipulation can greatly enhance your problem-solving skills, which is essential for coding interviews and real-world applications.
As we have seen, Python, with its versatile features, makes it relatively straightforward to handle strings compared to languages like C. However, the journey doesn’t stop here. To deepen your Python skills, consider taking upskilling courses from upGrad. upGrad offers a wide range of courses that cater to professionals looking to enhance their knowledge and stay competitive in the job market. Remember, in the ever-evolving world of technology, continuous learning is key to staying relevant and successful in your career.
1. Can I reverse a string in Python without using any inbuilt functions?
Yes, you can reverse a string in Python without using inbuilt function by using a for loop or while loop to iterate through the string and construct the reversed string.
2. What are the ways to reverse a string in Python using inbuilt function?
Python provides several built-in methods for string reversal, such as the [::-1] slicing method. However, there is no direct function like reverse() for strings.
3. How does string slicing work in Python?
String slicing in Python involves specifying a start, stop, and step value (default is 1) as indices to retrieve elements from the string. For example, string'[::-1] will return gnirts.
4. Are the Python string reversal methods similar to the ways you can reverse a string in C?
Some concepts like using a loop to reverse a string are common in both Python and C, but Python provides more built-in functions and methods like slicing, which are not available in C.
PAVAN VADAPALLI
Director of Engineering
Director of Engineering @ upGrad. Motivated to leverage technology to solve problems. Seasoned leader for startups and fast moving orgs. Working …Read More
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upGrad does not grant credit; credits are granted, accepted or transferred at the sole discretion of the relevant educational institution offering the diploma or degree. We advise you to enquire further regarding the suitability of this program for your academic, professional requirements and job prospects before enr...