FUNCTION

def is keyword to define function in python

f(x)=2x+1  # function denoted by f is given as 2x+1

# what is the output value of f if x=2
# ANSWER: f(2)=2*2+1=5

#In python, we define function using def keyword followed by function name and parantheses; 
#ending with colon
#Example:
def f(x):  # function definition in python with one parameter x
    y=2*x+1 # body section or block of code
    return y # out put section 

print(f(2))  # prints the output of the function f for x=2

5

function with two parameter

#def add(a,b): # a and b are two parameters
    #result=a+b  # the implementation section 
    #return result # output section

print(add(2,3))  # prints the result of the function add that takes  2 and 3 as arguments

5

function with three parameters

def add(a,b,c): # a, b, and c are three parameters
    result=a+b+c  # the implementation section 
    return result # output section

print(add(2,3,7))  # give error -type error as there is missing 1 required arguments

---------------------------------------------------------------------------

NameError                                 Traceback (most recent call last)

Cell In[5], line 1
----> 1 print(add(2,3,7))


NameError: name 'add' is not defined

print(add(2,3, 5))  

10

Functions are objects

r1=add(2,3,4)  # assigned to variable

r2=add(5,4,6)

def multiply(a,b):
    r=a*b
    return r

Invoking function

#To call a function, use its name followed by the parantheses.
#example:add() execute the code with in the function

#we can pass arguments (inputs) to the function with in the parantheses
#example: add(2,3,4)  # invoking function add with three arguments 

print(), len,type, etc.  # examples of built in function in python

def _add(a,b):
    y=a+b
    return y

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