Day 4: Python Functions, Scope & Modules
Step 1: Functions
Functions allow you to group code for reuse. They help organize your programs.
def greet(name):
print("Hello,", name)
greet("Alisha")
greet("John")
print("Hello,", name)
greet("Alisha")
greet("John")
Hello, Alisha
Hello, John
Hello, John
Step 2: Function Arguments & Return Values
Functions can accept arguments and return values:
def add(a, b):
return a + b
result = add(5, 7)
print("Sum =", result)
return a + b
result = add(5, 7)
print("Sum =", result)
Sum = 12
Step 3: Scope – Local vs Global
Variables defined inside a function are local. Variables outside are global.
x = 10 # global variable
def show():
x = 5 # local variable
print("Inside function:", x)
show()
print("Outside function:", x)
def show():
x = 5 # local variable
print("Inside function:", x)
show()
print("Outside function:", x)
Inside function: 5
Outside function: 10
Outside function: 10
Step 4: Modules
Modules are Python files that contain functions, variables, or classes which can be reused in other programs.
Example: math module for mathematical operations:
import math
print("Square root of 16 =", math.sqrt(16))
print("Pi =", math.pi)
print("Square root of 16 =", math.sqrt(16))
print("Pi =", math.pi)
Square root of 16 = 4.0
Pi = 3.141592653589793
Pi = 3.141592653589793
Step 5: PyCharm Project Example – Functions
Project layout and code demonstration:
Hello, Alisha
Sum = 12
Sum = 12
✔ End of Day 4 – Functions, scope, and modules understood. You can now organize and reuse your code effectively!