Functions-ii
Functions
A function is a block of reusable code that performs a specific task. It helps in code reusability, readability, and modularity.
Syntax for function:
def function_name():
# code
# Function without arguments:
def show():
print("This function does not take anything!")
# Function with arguments: a function can take one or more arguments
def add(a,b,c,d):
sum:int = a + b + c+ d
print("Sum: ",sum)
# Function can return a value
def multiply(a, b):
return a * b
result = multiply(4, 5)
print(result)
# Function with default argument: If function is called without argument default value, here "Everest", will be used for
# argument name
def mount(name="Everest"):
print("Hello", name)
mount()
mount("Lhoste")
Function with Keyword arguments:
def student(name, age):
print(name, age)
student(age=20, name="Ram")
Function with variable-length arguments: Any number of arguments can be supplied.
def total(*numbers):
sum = 0
for n in numbers:
sum += n
return sum
print(total(1, 2, 3, 4))
**kwargs (Keyword arguments):
def details(**info):
for key, value in info.items():
print(key, ":", value)
details(name="Sita", age=22, city="Kathmandu")
# Calling function from another function:
def square(x):
return x * x
def cube(x):
return square(x) * x
print(cube(3))
In Python a function can return more than one value :
def calculate(a, b):
return a + b, a - b, a * b
s, d, m = calculate(10, 5)
print(s, d, m)
Lambda function: one liner for simple tasks:
square = lambda x: x * x
print(square(6))
Recursive function: A function calling itself:
def factorial(n):
if n == 1:
return 1
return n * factorial(n - 1)
print(factorial(5))
Providing list (data structure: collection of elements) as arguments
def average(numbers):
return sum(numbers) / len(numbers)
print(average([10, 20, 30]))
Function as parameter: In Python function can be passed as parameter to another function
def operate(a, b, func):
return func(a, b)
def add(x, y):
return x + y
print(operate(3, 4, add))
Function to check if a number of even or odd
def even_odd(n):
if n % 2 == 0:
return "Even"
return "Odd"
print(even_odd(7))
Function to check if a number is prime
def is_prime(n):
if n <= 1:
return False
for i in range(2, n):
if n % i == 0:
return False
return True
print(is_prime(11))