Variables and Data Types

In this section, you will learn about variables and data types in Python. Variables are used to store and manipulate data, while data types define the nature of the data being stored. We will cover topics such as variable declaration and assignment, numeric data types, strings, Boolean data type, and type conversion.

Variable Declaration and Assignment

name = "John"
age = 25

Numeric Data Types

x = 10
y = 3.14
z = 2 + 3j

Strings

message = "Hello, World!"

Boolean Data Type

is_true = True

Type Conversion

a = 10
b = float(a)
c = str(a)
d = bool(a)

Python Tokens

In Python, a token is the smallest individual unit of a program. It could be a keyword, an identifier, a literal, a punctuation symbol, or an operator. Understanding Python tokens is essential for writing and understanding Python code. In this section, we will explore different types of Python tokens.

Keywords

Keywords are reserved words in Python that have a predefined meaning and cannot be used as identifiers (variable names or function names). Examples of keywords include `if`, `else`, `for`, `while`, `def`, `class`, and many more.

if x > 5:
    print("x is greater than 5")
else:
    print("x is not greater than 5")

Identifiers

Identifiers are names given to entities such as variables, functions, classes, modules, etc. In Python, an identifier must follow certain rules, such as starting with a letter or underscore, and can contain letters, digits, or underscores. It is case-sensitive.

x = 10
name = "Alice"
def greet():
    print("Hello, " + name)

Literals

Literals are constant values assigned to variables or used directly in the code. They represent fixed values such as numbers, strings, and boolean values.

x = 10          # Integer literal
name = "Alice"  # String literal
is_active = True  # Boolean literal

Punctuation Symbols

Punctuation symbols are special characters used for syntax and structure in Python code. They include parentheses, commas, colons, semicolons, brackets, etc.

x = (1, 2, 3)  # Parentheses
name = "Alice"  # Quotation marks

Operators

Operators are symbols used to perform operations on operands. Python supports various types of operators, such as arithmetic operators, comparison operators, logical operators, assignment operators, etc.

x = 10 + 5  # Addition operator
y = x > 5   # Comparison operator
is_valid = x > 0 and y  # Logical operator