PYTHON - Function

A function is a block of code which only runs when it is called.

You can pass data, known as parameters, into a function.

A function can return data as a result.

Calling a Function

def printmsg():
##def keyword use for defining function in python
print("my name is khan")
printmsg()

#output ::- my name is khan
############function with arguments################

Parameters

def name(n1):
print("my name is "+ n1)
name("rohan")

#output::- my name is rohan
#################################################################################

Default Parameter Value

def live(country = "India"):print("I am from" + country)
live("Sweden")
live("Dubai")
live()
live("Brazil")

########### Output ##############

I am from Sweden
I am from Dubai
I am from India
I am from Brazil

################################################################################

Return Values

#To let a function return a value, use the return statement:

def my_function(x):

  return 5 * x

print(my_function(3))

print(my_function(5))

print(my_function(9))

########### Output ##############

15

25

45 

################################################################################

Lambda Functions

In python, the keyword lambda is used to create what is known as anonymous functions. These are essentially functions with no pre-defined name. They are good for constructing adaptable functions, and thus good for event handling.

def myfunc(n):

  return lambda i: i*n

doubler = myfunc(2)

tripler = myfunc(3)

val = 11

print("Doubled: " + str(doubler(val)) + ". Tripled: " + str(tripler(val)))

########### Output ##############

Doubled: 22. Tripled: 33