[Edit] Python: Variables (#7436)

* [Edit] Python: Variables

* updated FAQs from PAA

* Update variables.md

* Update variables.md

---------

Author: Sriparno08

content/python/concepts/variables/variables.md

@@ -1,49 +1,150 @@
 ---
 Title: 'Variables'
-Description: 'A variable is used to store data that will be used by the program. This data can be a number, a string, a Boolean, a list or some other data type. Every variable has a name which can consist of letters, numbers, and the underscore character . The equal sign = is used to assign a value to a variable. After the initial assignment is made, the value of a variable can be updated to new values as needed. A variable can have a short name (like x and y) or a more descriptive name (age, grade, grocerylist). Rules for Python variables: - A variable name must start with a letter or the underscore character. It cannot start with a number. - A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _). - Variable names are case-sensitive (num, Num, and NUM are three different variables).'
+Description: 'Variables are used to store data that can be used and manipulated throughout a program.'
 Subjects:
   - 'Computer Science'
   - 'Data Science'
 Tags:
-  - 'Variables'
-  - 'Integers'
   - 'Booleans'
+  - 'Integers'
   - 'Strings'
+  - 'Variables'
 CatalogContent:
   - 'learn-python-3'
   - 'paths/computer-science'
-  - 'paths/data-science'
 ---
 
-A variable is used to store data that will be used by the program. This data can be a number, a string, a Boolean, a list or some other data type. Every variable has a name which can consist of letters, numbers, and the underscore character `_`.
+**Python variables** help in storing data that can be used and manipulated throughout a program. Unlike some other languages, Python doesn't require explicit declaration of a variable’s [data type](https://www.codecademy.com/resources/docs/python/data-types). Whether storing a number, a [string](https://www.codecademy.com/resources/docs/python/strings) of text, or even a complex data structure like a [list](https://www.codecademy.com/resources/docs/python/lists), variables act as containers for that information, allowing code to reference and reuse it.
+
+## Creating Python Variables
+
+The assignment [operator](https://www.codecademy.com/resources/docs/python/operators) (`=`) is used to create a Python variable:
+
+```py
+x = 10
+name = "Alice"
+is_active = True
+```
+
+In this example:
+
+- `x` stores an integer (`10`)
+- `name` stores a string (`"Alice"`)
+- `is_active` stores a Boolean value (`True`)
+
+Python automatically infers the type of data being assigned.
+
+## Modifying Python Variables
 
-The equal sign `=` is used to assign a value to a variable. After the initial assignment is made, the value of a variable can be updated to new values as needed.
+The assignment operator (`=`) can also be used to change the value of a Python variable after its creation:
 
-## Variable Names
+```py
+# Creating a variable
+x = 10
+
+# Changing the value of the variable
+x = 15
+```
+
+## Python Variable Naming Conventions
 
-A variable can have a short name (like `x` and `y`) or a more descriptive name (`age`, `grade`, `grocery_list`).
+A Python variable can have a short name (`x`, `y`, etc.) or a more descriptive name (`age`, `grade`, `grocery_list`, etc.).
 
-Rules for Python variables:
+Here are the rules to follow while naming Python variables:
 
-- A variable name must start with a letter or the underscore character. It cannot start with a number.
-- A variable name can only contain alpha-numeric characters and underscores (`A`-`z`, `0`-`9`, and `_`).
+- A variable name should begin with a letter or the underscore character. It cannot start with a number.
+- A variable name can only include alpha-numeric characters and underscores (`A`-`z`, `0`-`9`, and `_`).
 - Variable names are case-sensitive (`num`, `Num`, and `NUM` are three different variables).
 
-## Examples
+These are some valid variable names:
+
+```py
+my_var = 1
+_myvar = 2
+myVar3 = 3
+```
 
-These are all valid variable names and assignment:
+These are some invalid variable names:
 
 ```py
-user_name = "@sonny420"
-user_id = 100
-verified = False
+3var = 10    # Starts with a number (invalid)
+my-var = 20  # Contains a hyphen (invalid)
+if = "hello" # 'if' is a reserved keyword (invalid)
 ```
 
-A variable's value can be changed after assignment
+## Example 1: Basic Arithmetic with Python Variables
+
+This example adds two Python variables:
+
+```py
+a = 5
+b = 3
+
+sum_result = a + b
+
+print("Sum:", sum_result)
+```
 
-```codebyte/py
-points = 100
-points = 120
+The output generated by this code is:
 
-print(points)
+```shell
+Sum: 8
 ```
+
+## Example 2: Swapping Python Variables
+
+Python makes it easy to swap values between two variables:
+
+```py
+x = 10
+y = 20
+
+x, y = y, x
+
+print("x =", x)
+print("y =", y)
+```
+
+The output generated by this code is:
+
+```shell
+x = 20
+y = 10
+```
+
+## Codebyte Example: Using Python Variables in Strings
+
+Python variables can be used within strings using f-strings (Python 3.6+):
+
+```codebyte/python
+name = "Alice"
+
+age = 30
+
+print(f"My name is {name} and I am {age} years old.")
+```
+
+## Frequently Asked Questions
+
+### 1. What are the four types of variables in Python?
+
+Python defines four main types of variables based on their scope: local, global, instance and class. Here's how they work:
+
+- **Local variables**: Declared inside a function and accessible only within that function.
+- **Global variables**: Declared outside all functions and accessible throughout the program.
+- **Instance variables**: Belong to a specific object created from a class.
+- **Class variables**: Shared across all instances of a class.
+
+### 2. How to name Python variables?
+
+When naming variables in Python follow these rules:
+
+- Begin with a letter or underscore (`_`) and never with a number.
+- Use only letters, numbers, and underscores (no spaces or special characters).
+- Variable names are case-sensitive (`score`, `Score`, and `SCORE` are different).
+- Avoid using Python reserved keywords like `if`, `while`, or `class`.
+- Follow PEP 8 style guidelines and use `lowercase_with_underscores` for readability.
+
+### 3. How do you declare variable types in Python?
+
+Python uses dynamic typing, so you don’t have to declare types explicitly, the type is inferred when you assign a value.