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KEYWORDS AND IDENTIFIERS

In Python, keywords and identifiers are two important concepts that define the structure and
naming conventions of a program.

KEYWORDS

Keywords are reserved words with special
meanings in Python, used for tasks like control Python has 35 reserved keywords that cannot
flow (if, for, while), functions (def) and classes be used as variable names.
(class). They cannot be used as variable
names. Here is a list of Python keywords:

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
You cannot use keywords as variable names. For example, you cannot name a variable ‘if’ or ‘for’.

IDENTIFIERS

An identifier is a name used to uniquely identify a variable, function, class or object in Python. It
represents the values you store, like numbers or text.

Examples of Identifiers:

Variable identifiers: age, score, temperature

Function identifiers: print_message(), calculate_sum()
Class identifiers: Person, Student

VARIABLES IN PYTHON

In Python, variables store values that can be accessed or changed later. Their names are
identifiers and you don’t need to specify their type because Python is dynamically typed.

RULES FOR NAMING VARIABLES

When creating variable names, make sure to follow these rules:
Variable names can contain letters (a-z, A-Z), digits (0-9) and underscores (_).

Variable names must begin with a letter or an underscore (_), but not a number.
Variable names are case-sensitive, so ‘age’ and ‘Age’ are considered two different variables.

Variable names cannot use Python keywords (such as if, else, for) as variable names.
Variable names cannot contain spaces.

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