Python Keywords

Keywords in Python are reserved words that have special meanings and are used for specific purposes. These words are part of the Python syntax and cannot be used as identifiers (variable names, function names, etc.). Python has a set of keywords that are reserved, and you must use them only as intended.

List of Python Keywords

Python has the following built-in keywords:

Keyword	Description
False	Represents the boolean value False.
None	Represents a null value or "no value at all".
True	Represents the boolean value True.
and	Logical operator used to combine conditional statements.
as	Used to create an alias while importing a module.
assert	Used for debugging purposes to test if a condition is true.
async	Used to declare a function as asynchronous.
await	Used to pause the execution of async functions.
break	Terminates the nearest enclosing loop.
class	Used to define a new user-defined class.
continue	Skips the rest of the loop and starts the next iteration.
def	Used to define a new function.
del	Deletes objects in Python.
elif	Used for conditional branching; short for "else if".
else	Defines the alternative path in an if statement.
except	Used to catch and handle exceptions.
finally	Defines a block of code to be executed after a try block, regardless of whether an exception occurred.
for	Used to create a for loop.
from	Used to import specific parts of a module.
global	Used to declare a global variable.
if	Used to create a conditional statement.
import	Used to import a module.
in	Used to check if a value is present in a sequence (e.g., lists, tuples).
is	Used to test object identity.
lambda	Used to create anonymous functions.
nonlocal	Used to declare a non-local variable.
not	Logical operator to invert the truth value.
or	Logical operator used in conditional statements.
pass	A null statement; a placeholder for future code.
raise	Used to raise an exception.
return	Exits a function and returns a value.
try	Used to wrap a block of code that may throw an exception.
while	Used to create a while loop.
with	Used to wrap the execution of a block of code with methods defined by a context manager.
yield	Used to return a generator.

Understanding Python Keywords

Let's go through some of the most commonly used Python keywords with examples:

1. if, elif, and else

The if, elif, and else keywords are used for conditional branching in Python.

Code Example


# Conditional statements
x = 10
if x > 0:
    print("Positive")
elif x < 0:
    print("Negative")
else:
    print("Zero")

Output

Positive

2. for and while

The for and while keywords are used for looping in Python.

Code Example


# Using for and while loops
for i in range(3):
    print("For Loop:", i)

j = 0
while j < 3:
    print("While Loop:", j)
    j += 1

Output

For Loop: 0 For Loop: 1 For Loop: 2 While Loop: 0 While Loop: 1 While Loop: 2

3. def and return

The def keyword is used to define a function, and return is used to return a value from the function.

Code Example


# Function definition and return
def add_numbers(a, b):
    return a + b

result = add_numbers(5, 7)
print("Sum:", result)

Output

Sum: 12

4. try, except, and finally

The try block is used to catch exceptions, except handles the exception, and finally is executed regardless of whether an exception occurred or not.

Code Example


# Exception handling
try:
    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero")
finally:
    print("Execution complete.")

Output

Cannot divide by zero Execution complete.

5. class and object

The class keyword is used to define a class, and objects are instances of classes.

Code Example


# Defining a class and creating an object
class Car:
    def __init__(self, model, year):
        self.model = model
        self.year = year

my_car = Car("Toyota", 2020)
print("Car Model:", my_car.model)
print("Car Year:", my_car.year)

Output

Car Model: Toyota Car Year: 2020

Python keywords are essential to understanding the syntax and structure of Python code. These keywords have predefined meanings and uses, making it crucial to use them correctly. Understanding how to use Python keywords effectively will help you write clean and efficient Python code.