Step 1: Variables in Python

Variables store data that your program can use. Python is dynamically typed, so you don't need to declare types explicitly.

Note: Variable names cannot start with a number and are case-sensitive.

Step 2: Data Types

Python has several built-in data types:

• int – integers, e.g., age = 30
• float – decimal numbers, e.g., height = 5.6
• str – strings, e.g., name = "Alisha"
• bool – boolean, e.g., is_active = True
• list – ordered collection, e.g., numbers = [1,2,3]
• dict – key-value mapping, e.g., person = {"name":"Alisha", "age":30}

Step 3: Input and Output

Use input() to get user input and print() to display output:

Step 4: Operators

Python supports various operators:

• Arithmetic: +, -, *, /, %, **, //
• Comparison: ==, !=, >, <, >=, <=
• Logical: and, or, not
• Assignment: =, +=, -=, *=, /=

Step 5: PyCharm Project Example

Directory layout and simple script:

# main.py
a = int(input("Enter first number: "))
b = int(input("Enter second number: "))
print("Sum =", a + b)
print("Difference =", a - b)