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Iftakher Hossen
Iftakher Hossen

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The Building Blocks of Python: Variables, I/O, and Operators

Hello, Python enthusiasts! 🌟 Are you ready to take your first steps into the exciting world of Python programming? In this blog, we’ll cover three fundamental concepts that form the building blocks of Python programming. By the end, you’ll have a solid foundation to build upon as you continue your coding journey. These are the basics of a programming language; while the structure may vary in different languages, the concepts remain the same.

  • Variables and Data Types
  • Input and Output
  • Operators

Let’s dive in!

1. Variables and Data Types:

What is Variable?

Variables are containers where you can store data in your programs. Just like giving a name to a box so you know what's inside, you give your variables names to help you use their data later. One interesting fact about Python is that it's smart enough to figure out what type of data you're storing - you don't have to tell it whether you're storing numbers, text, or something else!
Examples:

name = "Hossen"     # String
grade = 97          # Integer
height = 6.1        # Float
is_student = True   # Boolean
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Varibale Naming Conventions:
Variable naming conventions are essential to maintain code readability and follow best practices. Here are the rules and conventions for naming variables in Python:

  • Must start with a letter or the underscore character
  • Cannot start with a number
  • Can contain letters, numbers, and underscores (A-z, 0-9, and _)
  • They are case-sensitive (age, Age and AGE are three different variables)
  • Cannot use any reserved words or keywords
  • If you have a longer name, use snake_case (preferred), camelCase, or PascalCase.

Variable Casting:
If you want to specify the data type of a variable, it can be achieved by casting.

x = str(5)      # x will be '5'
y = int(5)      # y will be 5
z = float(5)    # z will be 5.0
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Get the Type of Variable:
You can get the data type of a variable with the type() function.

x = 5
y = "Refat"
z = True
print(type(x))
print(type(y))
print(type(z))
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Assign Multiple Variables
Python allows you to assign values to multiple variables in one line:

x, y, z = "Orange", "Banana", "Cherry"
print(x)
print(y)
print(z)
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N.B. String variables can be declared either by using single or double quotes.

Types of Data

In programming, data types are an important concept. Variables can store different types of data, and each type has its own unique capabilities. Python comes with several built-in data types by default, which can be organized into the following categories:
Text Type: str
Numeric Types: int, float, complex
Sequence Types: list, tuple, range
Mapping Type: dict
Set Types: set, frozenset
Boolean Type: bool
Binary Types: bytes, bytearray, memoryview
None Type: NoneType

2. Input and Output

Input:
Python’s input() function allows you to capture input from the user. The input is always treated as a string unless explicitly converted.

name = input("What is your name? ")
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Output:
The print() function is used to display information. You can combine strings and variables for a more interactive experience.

age = 25
print("I am", age, "years old.")

# Using f-strings for adding dynamic value:
print(f"I am {age} years old.")
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3. Operators

Operators are special symbols or keywords that perform operations on data. They tell the computer what kind of operation or action to perform (eg. +, -, *, /).
Operands are the values or variables that operators work on - They're the data, the operator uses to do its job.
Python divides the operators into the following groups:

  • Arithmetic operators: Arithmetic operators are used with numeric values to perform common mathematical operations:
x + y      # Addition   
x - y      # Subtraction
x * y      # Multiplication 
x / y      # Division
x % y      # Modulus
x ** y     # Exponentiation
x // y     # Floor division
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  • Assignment operators: Assignment operators are used to assign values to variables.
x = 8
x += 8
x -= 8
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  • Comparison operators: Comparison operators are used to compare two values:
x == y     # Equal
x != y     # Not Equal
x > y      # Greater than
x < y      # Less then
x >= y     # Greater than or equal to
x <= y     # Less than or equal to
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  • Logical operators: Logical operators are used to combine conditional statements:
x < 5 and  x < 10      
# Returns True if both statements are true
x < 5 or x < 4          
# Returns True if one of the statements is true
not(x < 5 and x < 10)   
# Reverse the result, returns False if the result is true
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  • Identity operators: Identity operators are used to compare the objects, not if they are equal, but if they are the same object, with the same memory location:
x is y
# Returns True if both variables are the same object
x is not y
# Returns True if both variables are not the same object
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  • Membership operators: Membership operators are used to test if a sequence is presented in an object:
x in y
# Returns True if a sequence with the specified value is present in the object
x not in y
# Returns True if a sequence with the specified value is not present in the object
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  • Bitwise operators: Bitwise operators are used to compare (binary) numbers:
x & y      
# AND - Sets each bit to 1 if both bits are 1
x | y      
# OR - Sets each bit to 1 if one of the two bits is 1
x ^ y      
# XOR - Sets each bit to 1 if only one of the two bits is 1
x ~ y      
# NOT - Inverts all the bits
x << y     
# Zero fill left shift - Shift left by pushing zeros in from the right and letting the leftmost bits fall off
x <= y     
# Signed right shift - Shift right by pushing copies of the leftmost bit in from the left, and letting the rightmost bits fall off
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Congratulations on taking your first steps in Python programming! You've now learned the fundamentals of Variables, Input and Output, and Operators—essential building blocks, that every programmer needs to master. With this knowledge, you’re well on your way to writing more complex and powerful programs.

But don’t stop here! In the next blog of this series, we’ll dive into Control Flow, where you’ll learn how to make your programs more interactive and decision-driven. Stay tuned! If you have any questions, feel free to comment below. Don’t try to memorize the rules—dive in, and you will learn them perfectly by failing.

Happy coding! 🚀

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