𝗣𝘆𝘁𝗵𝗼𝗻 𝗳𝗼𝗿 𝗕𝗲𝗴𝗶𝗻𝗻𝗲𝗿𝘀: 𝗩𝗮𝗿𝗶𝗮𝗯𝗹𝗲𝘀 𝗮𝗻𝗱 𝗗𝗮𝘁𝗮 𝗧𝘆𝗽𝗲𝘀
You learned how to install Python and write your first program in Part 1. Now you must learn how to store information.
A variable is a name for a value in memory. Think of it as a labeled box. You put data inside the box and use the label to find it later.
Example: name = "Ramesh" age = 25
Python uses dynamic typing. This means you do not need to tell Python what kind of data a variable holds. It figures it out. You can even change the data type later.
x = 5 x = "hello"
This flexibility makes coding fast. However, you must watch your code to avoid mistakes.
Variable Name Rules:
- Start with a letter or an underscore (_).
- Do not start with a number.
- Use only letters, numbers, and underscores.
- Do not use Python keywords like class or if.
- Remember that names are case-sensitive. age and Age are different.
Use snake_case for your names. This means lowercase words with underscores. Example: first_name = "Ramesh"
Core Data Types:
- str: Text like "hello"
- int: Whole numbers like 25
- float: Decimals like 3.14
- bool: True or False
- list: An ordered collection
- dict: Key-value pairs
Use the type() function to check what you are working with. This helps you find errors quickly.
Python handles math easily:
- Addition
- Subtraction
- Multiplication
- / Division (always results in a float)
- // Floor division (removes the decimal)
- % Modulus (finds the remainder)
- ** Exponent
Sometimes you must change a type. This is called casting. If a user types 25, Python sees it as a string. You must convert it to an integer to do math.
Example: user_input = "25" age = int(user_input) print(age + 5)
Master these basics to avoid bugs. In Part 3, we cover strings and booleans.
Optional learning community: https://t.me/GyaanSetuAi