As we studied earlier, Python is a dynamically typed language, which means you don't have to declare the type of a variable when you create it. A variable in Python is a reserved memory location to store values. You create a variable by assigning a value to it using the = operator.
Creating Variables
a = 7 # Integer
b = 3.14 # Float
name = "Virat" # String
is_student = True # Boolean
Rules of Variable:
It must start with a alphabet or underscore ("_").
It can contain letters, digits, and underscores.
It's a Case-sensitive (e.g., name and Name are different).
Cannot be a reserved keyword (e.g., for, while, if, etc.).
Identifiers:
Name given to any programmable entity (python object, variables, functions, classes, decorators, generators).
Rules of Identifiers:
It must start with a alphabet or underscore ("_").
It can be alphanumeric but first character must be any alphabet or "_" .
No special characters allowed.
length of identifiers can be anything but as per PEP8((Python Enhancement Proposal) convention it must be 79 characters.
Keywords:
keywords are predefined words which have specific meaning and perform specific task.
Rules of keywords:
keywords cannot be variable because we cannot assign any values to them.
If we try to store any value, interpreter will raise syntax error.
There are totally 35 keywords in python.
Among them three are special keywords.
True, False, None are 3 special keywords which states value and starts with capital letters.