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
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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
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
Diving into the profound depths of Python programming, we often come across terminologies that set the foundation for the language. Among these, keywords and identifiers play an integral role in shaping the way we perceive and utilize Python.
In this tutorial, we'll embark on an illuminating journey to explore these cornerstones, unveiling their significance, characteristics, and application. While keywords anchor the language with predefined, unalterable terms, identifiers offer the flexibility to name variables, functions, and more. Together, Python keywords and identifiers are indispensable for any Python programmer aiming for mastery and precision.
At the heart of Python's intuitive syntax lie its keywords, a set of reserved words that drive the core functionality of the programming language. Each keyword is like a specialized tool, intricately designed for specific tasks, ensuring the language remains structured yet versatile. On the other side, we have identifiers, which bestow us with the freedom to define our constructs, be it naming a variable that stores data or a function that performs a sequence of operations. In this tutorial, we will offer a glimpse into the vast universe of Python keywords and identifiers, preparing you for the basics of programming.
In the vast landscape of programming languages, Python stands out with its clear syntax and concise code. A pivotal element contributing to this clarity is Python's keywords. As we delve deeper into understanding these, it becomes evident that keywords are more than just reserved words; they are the foundational pillars that uphold the language's structure.
Every programming language possesses its own set of reserved words, and Python is no different. These keywords have predefined meanings and serve specific functions, ensuring that developers have a standardized way of executing particular operations. What sets Python apart, however, is the intuitive nature of its keywords, making it easy for both beginners and seasoned programmers to adopt.
Keyword Category | Representative Examples | Core Functionality |
Control Flow | if, else | Steer program logic |
Loop | for, while | Drive iteration |
Exception Handling | try, except | Address code exceptions |
Class/Function | def, class | Frame functions & classes |
In Python, keywords are reserved words that have special meanings and purposes in the language. These words cannot be used as identifiers (variable names, function names, etc.) because they are already assigned specific roles within the language. Here is a list of Python keywords:
It's important to note that Python keywords are case-sensitive, which means that if is a keyword, but IF or If are not. Additionally, keep in mind that these keywords cannot be used as variable names, function names, or any other identifiers within your code.
For the most up-to-date and accurate list of Python keywords, you can refer to the official Python documentation or use the keyword module in Python:
Code:
import keyword
print(keyword.kwlist)
Example:
# Defining a function using the "def" keyword
def greet(name):
print("Hello,", name)
# Using the "if" and "else" keywords to perform conditional branching
def check_age(age):
if age < 18:
print("You are a minor.")
else:
print("You are an adult.")
# Using the "for" keyword to iterate through a list
fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
print(fruit)
# Using the "while" keyword for a loop with a condition
count = 0
while count < 5:
print("Count:", count)
count += 1
# Using the "return" keyword to return a value from a function
def add(a, b):
return a + b
# Using the "import" keyword to import a module
import math
print("Square root of 16:", math.sqrt(16))
# Using the "try", "except", and "finally" keywords for exception handling
try:
result = 10 / 0
except ZeroDivisionError:
print("Cannot divide by zero")
finally:
print("Exception handling complete")
# Using the "and" and "or" keywords for logical operations
x = True
y = False
print("x and y:", x and y)
print("x or y:", x or y)
Explanation:
# Using the "if" and "else" keywords to perform conditional branching
def check_age(age):
if age < 18:
print("You are a minor.")
else:
print("You are an adult.")
In this section, you've defined a function check_age that takes an age parameter. The function uses the if keyword to perform a conditional check. If the age is less than 18, it prints "You are a minor." Otherwise, it prints "You are an adult."
# Using the "for" keyword to iterate through a list
fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
print(fruit)
Here, you've created a list of fruits and then used the for keyword to iterate through each fruit in the list. The variable fruit takes on each value in the fruits list, and the loop prints each fruit's name.
# Using the "while" keyword for a loop with a condition
count = 0
while count < 5:
print("Count:", count)
count += 1
This code block demonstrates a while loop. It initializes a count variable to 0 and then enters a loop that prints the current value of count and increments it by 1. The loop continues as long as the count is less than 5.
# Using the "return" keyword to return a value from a function
def add(a, b):
return a + b
Here, you've defined a function add that takes two parameters a and b. The function returns the sum of a and b using the return keyword.
# Using the "import" keyword to import a module
import math
print("Square root of 16:", math.sqrt(16))
This code demonstrates the use of the import keyword. It imports the math module and then uses the math.sqrt() function to calculate and print the square root of 16.
# Using the "try", "except", and "finally" keywords for exception handling
try:
result = 10 / 0
except ZeroDivisionError:
print("Cannot divide by zero")
finally:
print("Exception handling complete")
This section uses the try, except, and finally keywords for exception handling. It attempts to perform a division by zero, which would raise a ZeroDivisionError exception. The except block catches the exception and prints an error message. The finally block always runs, whether an exception occurred or not.
# Using the "and" and "or" keywords for logical operations
x = True
y = False
print("x and y:", x and y)
print("x or y:", x or y)
Lastly, you're using the and and or keywords to perform logical operations. The code prints the result of the logical AND and logical OR operations between the boolean values x and y.
Code:
print("example of True, False, and, or, not keywords")
print(True and True)
print(True or False)
print(not False)
In Python, identifiers are names given to various programming elements such as variables, classes, modules, functions, etc. These names are used to uniquely identify these elements in your code. Here are the rules for creating valid identifiers in Python:
Here are some examples of valid identifiers in Python:
variable_name = 42
_total = 100
myFunction = lambda x: x * 2
MyClass = MyClassDefinition()
And here are some examples of invalid identifiers:
3var = "Invalid" # Identifier can't start with a digit
my-variable = 10 # Hyphens are not allowed in identifiers
class = "Class" # 'class' is a keyword and cannot be used as an identifier
Remember that using descriptive and meaningful names for your identifiers is important for code readability and maintainability.
It's worth noting that while underscores at the beginning of identifiers have no special meaning in terms of the Python language itself, a common convention is to use a single underscore at the beginning of an identifier to indicate that it's intended to be a "private" or "internal" variable, function, or method within a class or module. For example:
_internal_variable = 42
Code:
for j in range(1, 10):
print(j)
if j < 4:
continue
else:
break
Here are the rules for naming valid identifiers in Python:
Here are some examples of valid and invalid identifiers based on these rules:
Valid Identifiers:
variable_name = 42
_total = 100
my_function = lambda x: x * 2
MyClass = MyClassDefinition()
Invalid Identifiers:
3var = "Invalid" # Starts with a digit
my-variable = 10 # Contains hyphen
class = "Class" # Same as a keyword
Code:
for i in range(1,7):
if i == 1:
print('One')
elif i == 2:
print('Two')
else:
print('else block execute')
Code:
def upGrad():
p=20
if(p % 2 == 0):
print("given number is even")
else:
print("given number is odd")
upGrad()
Having navigated through the intricate nuances of Python's keywords and identifiers, we now appreciate their pivotal role in shaping our programming journey. Their synergy balances the language, with keywords providing the foundational rigidity and identifiers infusing dynamism.
As we continue to evolve in our Python journey, understanding such elements becomes instrumental in writing efficient, clean, and optimized code. However, the road to mastering Python doesn't end here. The realm of programming is vast and ever-evolving. For those enthusiastic professionals who resonate with a hunger for knowledge, upGrad offers a multitude of upskilling courses. Dive deeper, explore further, and let your coding journey flourish with upGrad.
1. What are keywords in Python?
Keywords in Python are reserved words with specific functions and meanings, essential in determining the structure of the language.
2. What is the difference between keywords and identifiers in Python?
While keywords are reserved words with predefined meanings, identifiers are user-defined names given to entities like variables and functions.
3. All keywords in Python are in which case?
All keywords in Python are in lowercase, emphasizing the language’s case sensitivity.
4. How are identifiers in Python chosen?
Identifiers are user-defined and should be chosen descriptively, avoiding any conflict with existing keywords.
5. Why is understanding keywords essential for advanced Python programming?
Grasping keywords ensures streamlined coding, as these words help structure the language, facilitating the creation of efficient programs.
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...