Python Functions.md

Normal functions

def my_function():
  print("hello world")

my_function()

 hello world

parameters and arguments

def testAutoInfo(car_name,car_engine,car_price): #parameters
  
  list_details = [car_name,car_engine,car_price]
  print("\nyour car details")
  for x in list_details:
    print(x,end=" ")
  

testAutoInfo("BMW","v12","1234") #arguments 
testAutoInfo("Audi","v8","12Lakhs")

your car details
BMW v12 1234 
your car details
Audi v8 12Lakhs 

Arbitrary Arguments, *args

If you do not know how many arguments that will be passed into your function, add a * before the parameter name in the function definition. function will receive a tuple of arguments, and can access the items accordingly

def my_function(*x):
  print(x) #function will receive a tuple of arguments
  for i in x:
    print(i)

my_function(1,"1we",3j,4,5)
my_function(23,"12wqa",334,2j)

(1, '1we', 3j, 4, 5)
1
1we
3j
4
5
(23, '12wqa', 334, 2j)
23
12wqa
334
2j

keyword arguments

key = value syntax

def my_function(T1,T2,T3,T4):
  print("fn = "+T1)
  print("fn2 = "+ str(T4))

my_function(T1="@we",T2="12",T3=12330,T4=12+1j)

fn =@we
fn2 =(12+1j)

Arbitrary Keyword Arguments, **kwargs

key = value pair format

If you do not know how many keyword arguments that will be passed into your function, add two asterisk: ** before the parameter name in the function definition

def test(**test1):
  print(type(test1))
  for i,y in test1.items():
    print(i+" "+str(y))

test(BrandName="Audi",CarName="A8L",Engine="v12")
test(BrandName="BMW",CarName="780li",Engine="v8")

<class 'dict'>
BrandName Audi
CarName A8L
Engine v12
<class 'dict'>
BrandName BMW
CarName 780li
Engine v8

default parameter and return value

#we can also set default value for our paramaters 
def my_function(x=5):
  return 5*x  # will return some value 

print(my_function(3))
print(my_function())

15
25

pass statement

if no statement just put pass in there

def test_this():
  pass

test_this()

Recursion

function calls itself based on stack with no base condition causes something called stack overflow

def testQ(n):
  print(n)
  if n>1:
   testQ(n-1)

testQ(5)

5
4
3
2
1

def testA(i):
  print(i)
  if i<10:
    testA(i+1)

testA(1)

1
2
3
4
5
6
7
8
9
10

def Test1(k):
  if k>0:
    val=k+Test1(k-1)
    print(val)
  else:
    val=0
  return val

Test1(6)

1
3
6
10
15
21