Python

Functions in pythons:

Creating function:

def function_name():
    '''
       Documentation regarding function work and parameter information
    '''
    #Function operation implementation

keyword	Details
def	definition of function.
function_name	Function name. Snake casing is use as standard for function name. (Snake casing is all character is in lower letter and connected with spaces
:	A colon indicate upcoming intended block is implementation for function.
’’’ Documentation ‘’’	Documentation regarding function work and parameter information

args (Variable argument list) keywords:

Function Decalaration:

def average(*args):
    '''
       Average function. Taking number as args input and return their average
    '''
    return sum(args) / len(args)

Calling example, -

  print(f'Total Average for (1, 2, 3, 4, 5) is : {average((1, 2, 3, 4, 5))}')

kargs (Key-Value Paired argument) keyword:

Function Decalaration:

def showStudentInformation(**kargs):
    '''
       show student information function show student name, address, marks and Percentage
    '''
    print(f'========== Student Information ==========')
    print(f'Name         : {kargs["name"]}')
    print(f'Address      : {kargs["address"]}')
    print(f'Marks        : {kargs["marks"]}')
    print(f'Percentage   : {(sum(kargs["marks"]) / len(kargs["marks"])) * 100.00}')

Calling example, -

  showStudentInformation({'name:'John Simth', 'address': 'Pune', 'marks':[120,140,130]})

map built-in function

• Map modifies the list with a normal logic that produces another list

# square method
def square(num):
    return num ** 2

#Map to return square of each element of list.
print(map(square, [1, 2, 3, 4, 5]))
squareList = list(map(square, [1, 2, 3, 4, 5]))
print(squareList)

Output => [1, 4, 9, 16, 25]

filter built-in function

• Filter modifies the list with conditional logic that filters out some elements

  #is even number function
  def isEvenCheck(num):
    return num ** 2
  

#Filter to find out even number from list
print(filter(isEvenCheck, [1, 2, 3, 4, 5, 6]))
evenList = list(filter(isEvenCheck, [1, 2, 3, 4, 5, 6]))
print(evenList)

Output => [2, 4, 6]

lambda keyword

-syntax

    square = lambda num : num ** 2

keyword	Details
square	variable name
lambda	lambda keyword
num	Input variable
:	A colon indicate upcoming intended block is implementation for function.
num ** 2	method body

Example-1 Converting above mentioned square function into lambda expression, -

myNumList = [1,2,3,4,5,6]
mySquareList = list(map(lambda num: num ** 2, myNumList))
mySquareList

Output:

[1, 4, 9, 16, 25, 36]

Example-2 Converting above mentioned isEven function into lambda expression, -

myNumList = [1, 2, 3, 4, 5, 6]
myEvenList = list(filter(lambda num: num % 2 == 0, myNumList))
myEvenList

Output:

[2, 4, 6]

Example-3 Reverse string of list, -

myNameList = ['Bhushan', 'Sandip', 'Neel', 'Lavanya', 'Nidhi']
myResultList = list(map(lambda name: name[::-1], myNameList))
myResultList

Output:

['nahsuhB', 'pidnaS', 'leeN', 'aynavaL', 'ihdiN']

Back

---

python-documentation is maintained by ravaan-techky.

---