List of reserved keywords in Python and how to check and display the words

Python has a list of keywords which it uses for its syntax and internal processing. We can’t use these reserved words in our program as variable names or function names or as identifiers.

List of 35 reserved keywords in Python

This list may change with different versions of Python

`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`

Python reserved words list using keyword module with methods to check words

How to know if the name is included in the reserved key word list or not ?

We are checking the key word ( variable name ) nonlocal

import keyword
print(keyword.iskeyword('nonlocal')) # True

Display the full list of reserved keywords

We can display full list of reserved keywords in Python ( current version )

import keyword 
print(keyword.kwlist)

To know the number of words in the reserved keyword list

print(len(keyword.kwlist)) # 35  ( may change )

If we use any of the above listed words as variable then we will get the error message SyntaxError: invalid syntax

def is a reserved word ( for defining functions )
This line will generate error

def=45

SyntaxError: invalid syntax

Python variables are case sensitive, so break is a reserved keyword but Break is not. Check the outputs below.

import keyword
print(keyword.iskeyword('break')) # True
print(keyword.iskeyword('Break')) # False

Reserved Words and Syntax Highlighting:

Mostlikely reserved words are typically highlighted in different Integrated Development Environments (IDEs) and text editors. This helps in syntax highlighting for code readability and error prevention.

Understanding why they are reserved:

These reserved words have specific meanings and functionalities in Python, like controlling control flow, defining loops, handling data types, etc. Using them for other purposes would clash with their existing roles and create confusion. Remember, using descriptive variable names and avoiding reserved words makes your code more readable and maintainable for yourself and others.

Download the above full source code from Github or run the code in your Google colab platform.

https://github.com/plus2net/Python-basics/blob/main/online_class_reserved_words_v1.ipynb

Questions

What are Python reserved words?
How many reserved words are in Python 3?
Can a Python reserved word be used as an identifier?
What is the purpose of reserved words in Python programming?
Are there any new reserved words introduced in Python 3.8?
How do reserved words differ from built-in function names in Python?
Can the list of Python reserved words change in future versions?
What are some examples of Python reserved words used for control flow?
How are reserved words highlighted in Python IDEs?
Are there reserved words unique to Python that are not found in other programming languages?
How does Python's reserved word `yield` function in generator definitions?
What role do reserved words play in Python's exception handling mechanism?
How can I avoid syntax errors when using Python reserved words in my code?
In what scenarios are the reserved words `async` and `await` used in Python?
Is there a reserved word in Python for declaring global variables within a function?
How do the reserved words `True`, `False`, and `None` differ from other reserved words in Python?
What is the significance of the reserved word `nonlocal` in nested function definitions?
Are Python reserved words case-sensitive?
How do the reserved words `import` and `from` facilitate module usage in Python?
What best practices should developers follow when learning Python reserved words?

Python reserved words listing and checking #python #reserwords
14-Feb-2024

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Reserved words in Python