Variables in Python
- A variable is a symbolic name that references a value in memory.
- In Python, variables are used to store data values.
- They act as labels for memory locations, allowing you to access and manipulate data easily.
- In Python, you don’t have to specify the data type of a variable because it is automatically determined based on the assigned value.
# Variable assignment name = "Kunal" age = 17 height = 5.6 # Variable usage print("Name:", name) print("Age:", age) print("Height:", height)
Variable Naming Rules
- Variable names must start with a letter (a-z, A-Z) or an underscore (_).
- The rest of the variable name can consist of letters, numbers (0-9), and underscores.
- Variable names are case-sensitive (kunAl and kunal are different variables).
- You can assign values to variables using the assignment operator (=).
- The variable on the left of the = sign receives the value on the right.
a = 50 b = 60 total = a + b
You can assign multiple variables on a single line.
a, b, c = 10, 20, 30
Python allows you to swap the values of variables without using a temporary variable.
a, b = 10, 20 a, b = b, a # Swap values: a = 20, b = 10
Global vs. Local Variables:
- Variables declared outside functions are known as global variables. They can be accessed from anywhere within the program.
- On the other hand, variables declared inside functions are called local variables. They are only accessible within that specific function.
global_var = 10 def my_function(): local_var = 20 print(global_var) # Access global variable print(local_var) # Access local variable