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
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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
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
Python's versatility and power as a programming language are well-known. To harness its full potential, you need to understand the Python functions scope. In this extensive tutorial, we will delve deep into the intricacies of Python function scope, offering solutions to frequently asked questions while presenting hands-on illustrations. Let's begin our exploration!
In the realm of Python programming, 'scope' pertains to the extent of access to variable names within a program. Python employs a system comprising four key scopes, denoted by the acronym LEGB, which encompasses Local, Enclosed, Global, and Built-In. These distinct scopes establish a hierarchy that dictates the sequence in which the Python interpreter explores and retrieves variable names and their associated values. This systematic approach ensures the precise identification of variables based on the order of these scopes.
The LEGB rule is a fundamental principle in Python's scope resolution. It establishes a hierarchy of scopes, dictating the sequence in which the interpreter attempts to retrieve a variable's name and value. It starts with the Local scope, where the variable is defined within a specific function. If the variable is not found there, the interpreter proceeds to the Enclosed scope, which relates to variables in enclosing functions. Following that, it looks at the Global scope, where variables are defined at the module or script level. Lastly, if the variable is not found in any of the previous scopes, there - in the Built-In scope, which contains Python's predefined names and functions. This systematic approach ensures that the correct variable is retrieved based on the order of these scopes.
Step 1: Establishing Local Variables
Local variables are declared within a function, and they are accessible and modifiable only within that specific function. They play a crucial role in encapsulating data within a function and avoiding naming conflicts in larger programs.
Step 2: Example
Let's illustrate a straightforward case of a local variable in Python:
In this scenario, my_var is explicitly declared as a local variable, confining its reach solely within the boundaries of the my_function's scope.
Step 3: Precedence
The concept of variable scope is crucial for understanding how variables are accessed and prioritized within a program. This concept establishes a hierarchy among different scopes, with local scope holding the highest priority. When a variable is declared within a particular function, it is classified as a local variable. Local variables hold a higher priority in Python than variables in other scopes, including enclosed, global, and built-in.
This implies that when a local variable shares an identical name with a global variable, the local variable takes precedence and is employed within the function. In simpler terms, the local scope is prioritized over the global scope. This behaviour guarantees that the variable defined within the function is the one that is both accessed and modified, effectively creating isolation from the global variable with the identical name.
Step 1: Nested Functions
The enclosed scope involves variables in nested functions. In Python, you can define functions within functions, creating a hierarchical structure of scopes. Variables defined in an outer function can be accessed in inner functions.
Step 2: Example
Step 3: Precedence
Enclosed scope variables have the second-highest precedence. If a variable isn't found in the local scope, Python looks in the enclosed scope before checking the global scope.
Step 1: Variables Outside of Functions
Global scope includes variables defined outside of functions. "These variables can be accessed from any part of your code, making them ideal for storing data that requires sharing across different sections of your program."
Step 2: Example
Step 3: Precedence
Global scope variables have the third-highest precedence. If a variable is not found in local or enclosed scopes, Python looks in the global scope.
Step 1: Predefined Names and Functions
The built-in scope encompasses Python's predefined names and functions. These names and functions are always accessible. They include fundamental functionalities for Python programs and provide a foundation for the language.
Step 2: Example
Step 3: Precedence
Built-in scope variables have the lowest precedence. "In cases where a variable is not located within the local, enclosed, or global scopes, Python will conduct a search in the built-in scope."
Step 1: Declaring Local Variables
Declaring a local variable is straightforward—simply assign a name to it within a function. Using meaningful variable names enhances the readability of your code."
Step 2: Assigning Values
"The next step is to give a local variable a value once it has been defined. Different data kinds, including integers, texts, and lists, may be included in this value.
Step 3: Local Scope
Remember that a local variable is accessible and modifiable only within the function where it's defined. Attempting to access it outside the function will result in a "NameError."
"In Python, when you attempt to access a variable, the Python interpreter follows a specific order of scope resolution known as the LEGB rule. This means it searches for the variable sequentially, starting with the local scope, followed by the enclosed scope, the global scope, and finally, the built-in scope. The first occurrence of the variable that the interpreter finds within these scopes is the one that will be retrieved."
Step 1: Hierarchy of Variable Resolution
The LEGB rule is a hierarchy Python follows to determine the scope of a variable. LEGB stands for Local, Enclosed, Global, and Built-in. Python searches for a variable in this order.
Step 2: Variable Resolution
"When referencing a variable in your Python code, the process begins by checking the local scope. If the variable isn't located there, Python proceeds to examine the enclosed scope, followed by the global scope, and lastly, the built-in scope."
Step 3: Understanding Variable Precedence
Understanding the LEGB rule is crucial for variable resolution. It ensures that the correct variable is used based on the defined scopes, preventing naming conflicts and unexpected behaviour in your code.
Step 1: Modifying Enclosing Scope Variables
The nonlocal keyword allows you to modify variables in an enclosing (non-global) scope. This is particularly useful when dealing with nested functions. It ensures you can update variables in the nearest enclosing scope.
Step 2: Preventing Scope Confusion
The nonlocal keyword helps prevent scope confusion by specifying that a variable should be modified in an enclosing scope rather than creating a new local variable with the same name.
Step 3: Practical Examples
Let's consider an example:
Step 1: Declaring Global Variables
The global keyword is used to declare a variable as global. "The global keyword in Python facilitates the accessibility and alteration of a variable from any part of your code. Employ the global keyword when you intend to modify a global variable while operating within a function." The Global scope encompasses variables defined at the module or script level, while the Built-In scope holds Python's predefined names and functions.
Step 2: Avoiding Variable Shadowing
Using the global keyword ensures that you are working with the global variable rather than creating a new local variable with the same name. This helps avoid variable shadowing.
Step 3: Practical Example
In conclusion, a strong grasp of Python function scope is essential for writing efficient and bug-free code. "By gaining a comprehensive understanding of the four distinct scopes in Python (local, enclosed, global, and built-in), grasping the LEGB rule, and mastering the utilization of nonlocal and global keywords, you can enhance your proficiency in Python programming."
The LEGB establishes a precise sequence for the interpreter to search for variable names and their corresponding values. When referencing a variable in Python, the interpreter follows a sequential search through the Local, Enclosed, Global, and Built-In scopes. It starts with the Local scope, which pertains to variables defined within a specific function. If the variable is not found there, the interpreter proceeds to the Enclosed scope, which includes variables in enclosing functions.
The Global scope encompasses variables defined at the module or script level, while the Built-In scope holds Python's predefined names and functions. This systematic approach ensures that Python accurately identifies variables based on the order of these scopes, providing clarity and consistency in variable resolution across the code.
Q1. What is the outcome when attempting to retrieve a local variable beyond the function where it's declared?
Trying to access a local variable outside its defining function will lead to a "NameError" due to the variable being out of scope.
Q2. Is it possible to use identical variable names in separate scopes without causing conflicts?
Indeed, it is permissible to employ the same variable names in distinct scopes without encountering any clashes. Each scope has its namespace.
Q3. What is the significance of the LEGB rule in Python?
The LEGB rule defines the order in which Python looks for a variable: Local, Enclosed, Global, and Built-in. Understanding this rule is crucial for variable resolution.
Q4. Are there any restrictions on modifying global variables within a function?
To alter a global variable within a function, you must specify it as "global" within the function to indicate your intention to manipulate the global variable.
Q5. What does the built-in scope in Python hold in terms of importance?
The built-in scope contains Python's predefined names and functions, providing fundamental functionalities for Python programs. Built-in names and functions are always accessible.
Q6. How can I create a variable with global scope in Python?
"To establish a variable with global scope in Python, you should declare it outside the confines of functions. This approach grants the variable universal accessibility throughout your code, designating it as a global variable."
Q7. What are the potential issues of using global variables extensively in Python?
Extensively using global variables in Python can lead to several issues, including code complexity, increased chances of naming conflicts, and reduced modularity. It's generally recommended to use global variables sparingly to maintain clean and maintainable code.
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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...