Python Variables, Data Types, and Basic I/O – A Beginner’s Guide (2025)

What Are Variables in Python?

In Python, a variable functions similarly to a container for data values. Python, in contrast to several other programming languages, determines a variable’s data type automatically depending on the value supplied to it..

Syntax:

pythonCopyEditvariable_name = value

Example:

pythonCopyEditname = "Alice"
age = 25
is_student = True

You can also read:-  What is Python?

Best Practices:

• Make use of appropriate variable names, such as total_price and user_name.
• Observe the snake_case naming scheme.
• Don’t name variables with Python reserved keywords.

Data Types in Python

Python provides a number of built-in data types and is a dynamically typed language.

🔹 1. Numeric Types

• int – Integer numbers
• float – Decimal numbers
• complex – Complex numbers

pythonCopyEditx = 10          # int
y = 3.14        # float
z = 2 + 3j      # complex

🔹 2. Text Type

• str – String of characters

pythonCopyEditgreeting = "Hello, Python!"

🔹 3. Boolean Type

• bool – Represents True or False

pythonCopyEditis_active = True

🔹 4. Sequence Types

• list – Ordered and mutable
• tuple – Ordered and immutable
• range – Sequence of numbers

pythonCopyEditmy_list = [1, 2, 3]
my_tuple = (4, 5, 6)
my_range = range(1, 5)

🔹 5. Mapping Type

• dict – Key-value pairs

pythonCopyEditstudent = {"name": "John", "age": 22}

🔹 6. Set Types

• set – Unordered and no duplicate elements

pythonCopyEditmy_set = {1, 2, 3, 3}

🔹 7. None Type

• Represents the absence of a value

pythonCopyEditx = None

Basic Input and Output in Python

🟡 Input from the User

Use the input() function to get information from the user. By default, it gives back a string.

pythonCopyEditname = input("Enter your name: ")
print("Hello,", name)

Convert input to another data type:

pythonCopyEditage = int(input("Enter your age: "))
print("You will be", age + 1, "next year.")

Output in Python

The print() function is used to display output.

pythonCopyEditprint("Welcome to Python Programming!")

Format strings using:

• f-strings (Python 3.6+)

pythonCopyEditname = "Alice"
print(f"Hello, {name}")

• .format() method

pythonCopyEditprint("Hello, {}".format(name))

Mini Project: Greet the User

pythonCopyEdit# A simple input/output example
name = input("What's your name? ")
age = int(input("How old are you? "))
print(f"Hi {name}, you are {age} years old!")

Conclusion

Every newcomer studying Python must comprehend variables, data types, and fundamental I/O operations. These ideas serve as the cornerstone for creating dynamic, readable, and useful programs.

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