Function of python
Let's understand about function of Python
some function example:
type()
print()
input()
int()
why we use function
i. reduce duplicacy in code
ii. makes our code easy to understand
iii. wrapping our code into small boxes
Let's understand with example:
we call function 1 time
def greet():
print("Hello world")
print("Welcome to AttainU")
print("print some text")
greet()
output:
Hello world
Welcome to AttainU
print some text
Welcome to AttainU
print some text
def is a Keyboard.
greet is an identifier. Identifier can any name you give.
greet() call the function.
we call function 2 times & that's why its run 2 times
def greet():
print("Hello world")
print("Welcome to AttainU")
print("print some text")
greet()
greet()
output:
Hello world
Welcome to AttainU
print some text
Welcome to AttainU
print some text
Hello world
Welcome to AttainU
print some text
Welcome to AttainU
print some text
we call function many times as we want.
n = int(input("Enter value of n :"))
s = 0
for i in range(1, n+1):
s+= i ** 3
print(s)
input: 5
output: 225
Above code we write under a function
def sum_of_cubes():
n = int(input("Enter value of n :"))
s = 0
for i in range(1, n+1):
s+= i ** 3
print(s)
sum_of_cubes()
input: 5
output: 225
Use the function in some others files without writing same code.
from func import sum_of_cubes
sum_of_cubes()
Another Function example
def add(a,b):
s = a + b
return s
res = add(2,4)
print(res)
output: 6
Pascal Tringal
## Pascal tringle
n = int(input("enter a value: "))
for row in range(1,n+1):
for stars in range(row):
print("*", end = " ")
print()
output:
enter a value: 5
*
* *
* * *
* * * *
* * * * *
*
* *
* * *
* * * *
* * * * *
Another Function example:
def test(n):
for i in range(n,1,-1):
return i
break
return 0
x = test(10)
print(x)
output: 10
Another Function example:
## Star (15)
def star(n):
lin = 1
while lin<=n:
no_of_stars = 0
while no_of_stars<lin:
print("*", end=" ")
no_of_stars += 1
print()
lin += 1
star(3)
You can Multiply String with a number
print("Hello world" * 3)
print("Hello world \n" * 3)
output:
Hello worldHello worldHello world
Hello world
Hello world
Hello world
Print Star
def star(n):
for line in range(1, n+1):
print("*" * line)
star(5)
output:
*
**
***
****
*****
**
***
****
*****
Function Example:
def ABC():
sum = 10
for i in range(10):
sum = 0
print(sum)
ABC()
output: 0
sum = 0
def ABC():
sum = 10
for i in range(10):
sum = 5 ## this is local variable
ABC()
print(sum)
output: 0
output 0 because this is out of defination.
Global Variable
s = 5
# Global Variable
def ABC():
print(s)
# Local Variable
ABC()
print(s)
Output:
5
5
s = 5
# Global Variable
def ABC():
print(s)
# Local Variable
ABC()
Output:
5
Another Global Variable
s = 5
# Global Variable
def ABC():
s = 10
print(s)
# Local Variable
ABC()
print(s)
Output:
10
5