How Many Keyword in Python (With Examples)

def for():
Invalid Function Name!

This will throw a SyntaxError.

2. Case Sensitivity

if = 10  # Invalid, raises SyntaxError
If = 10  # Valid, as "If" is not a keyword

3. Cannot Be Re-Defined

True = False  # Invalid, raises SyntaxError

4. Only Lowercase and Camel Case: 

global = "variable"  # Invalid
TRUE = "value"       # Valid, as TRUE is not a keyword

5. No Additions or Deletions

for i in range(5):  # 'for' is used in loop statements
    print(i)

6. Avoid Confusion with Identifiers:

def class_():
    pass  # Valid, but confusing and discouraged

List of keywords in Python

Python keywords might be different depending on the version you're using, as in, some new ones might get introduced or some existing ones might not be there. So it is better to always check what keywords are there. You can do that with the help of the 'keyword' module like this:

import keyword
print(keyword.kwlist)

When you run this code in Python Compiler you will get a list of Python keywords printed as in the below output:

Output

['False', 'None', 'True', 'and', 'as', 'assert', 'async', 'await', 'break', 'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'finally', 'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass', 'raise', 'return', 'try', 'while', 'with', 'yield']

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How to Identify Python Keywords

• Use an IDE With Syntax Highlighting

• Use Code in a REPL to Check Keywords

• Look for a SyntaxError

Classification of Python Keywords

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Python Keywords and Their Usage

1. Value Keywords

• True, False- They both are used in logical expressions and represent the boolean values 'True' and ' False'.
• None- It is used to represent that there is no value or it is null.

Example of Value keywords

print(True)
print(False)
print(None)

Output

True
False
None

2. Operator Keywords

• and-It will return 'True' when both the operands are 'True'.
• or-It will return 'True' when at least one of the operand is 'True'.
• not-It will return the opposite of the operand.
• in-It checks that whether a specified value is present in the given sequence.
• is-It compares the identity of objects.

Example of Operator keywords

a = True
b = False
print(a and b)
print(a or b)
print(not a)
print(5 in [1, 2, 3, 4, 5])
print(5 is 5)

Output

False
True
False
True
True

3. Control Flow Keywords

• if-It will execute a code block if the condition is 'True'.
• elif-It is the short form of 'else if'. It will put another alternative condition for checking if the 'if' condition is 'False'.
• else-It will execute a code block if none of the conditions are 'True'.

Example of Control Flow keywords

x = 10
if x > 5:
    print("x is greater than 5")
elif x == 5:
    print("x is equal to 5")
else:
    print("x is less than 5")

Output

x is greater than 5

4. Iteration Keywords

• for-It iterates over the elements of a specified sequence.
• while-It will execute a code block as long as the condition is 'True'.
• break-It is used for terminating the loop before completion.
• continue-It is used for skipping the current iteration and continue with the next one.
• else-It will execute a code block when the has completed without a 'break' statement.

Example of Iteration keywords

for i in range(5):
    if i == 3:
        break
    print(i)
else:
    print("Loop completed successfully")

Output

0
1
2

5. Structure Keywords

• def-It defines a function.
• class-It defines a class.
• with-It uses context managers to simplify resource management.
• as-It renames or aliases imported modules or objects.
• pass-It indicates that no action needs to be taken.
• lambda- It creates an anonymous function.

Example of Structure keywords

def example_function():
    pass

class ExampleClass:
    pass

with open('example.txt', 'r') as file:
    data = file.read()

lambda_func = lambda x: x * x
print(lambda_func(5))

Output

25

6. Returning Keywords

• return-It will exit a function and may also return a value.
• yield-It will stop the execution of a function and will return a value to the caller while the state of the function remains constant.

Read More: Functions in Python

Example of Returning keywords

def example_function():
    return 42

def generator_function():
    yield 1
    yield 2
    yield 3

print(example_function())
print(list(generator_function()))

Output

42
[1, 2, 3]

7. Import Keywords

• import-It will import a whole module.
• from-It will import specific symbols from a module.
• as-It will alias the imported symbols or modules.

Example of Import keywords

import math
from datetime import datetime as dt

print(math.pi)
print(dt.now())

Output

3.141592653589793
<current date and time>

8. Exception-Handling Keywords

• try-It will start and check a code block that may have an exception but not execute it.
• except-It is used for checking and handling exceptions.
• raise- It will raise an exception.
• finally-It will execute a code no matter if any exceptions occur or not.
• else-It will execute the code if there is no exception occurring in the 'try' block.
• assert-When the condition is 'False', an 'AssertionError' is raised to assert a condition.

Example of Exception-Handling keywords

try:
    x = 1 / 0
except ZeroDivisionError:
    print("Error: Division by zero")
else:
    print("No error occurred")
finally:
    print("Cleanup code")

assert 2 + 2 == 4, "Math is broken"

Output

Error: Division by zero
Cleanup code

9. Asynchronous Programming Keywords

• async-It is used for defining a coroutine function.
• await-It will pause the execution of a coroutine function until its own coroutine function completes.

Example of Asynchronous Programming keywords

import asyncio

async def example_coroutine():
    await asyncio.sleep(1)
    print("Async function executed")

async def main():
    await example_coroutine()

asyncio.run(main())

Output

Async function executed

10. Variable Handling Keywords

• del-It will delete a variable from a collection.
• global-It is used for declaring a variable with a global scope.
• nonlocal-It is used for declaring a variable with a scope of the nearest function just outside the current one.

Example of Variable Handling keywords

x = 10
print(x)
del x
print(x)  # Raises NameError because x is deleted

Output

10
NameError: name 'x' is not defined

Summary