in and not in Membership operators check presence of elements inside a sequence or iterator in Python

x in my_iterable

my_iterable : iterable input.
Return boolean value True or False. If x is found inside my_iterable then True is returned otherwise False.

x not in  my_iterable

my_iterable : iterable input.
Return boolean value True or False. If x is found inside my_iterable then False is returned otherwise True.

Using list

my_list=[3,4,5,8,3]
if(9 not in my_list):
  print("Yes it is NOT Present")
else:
  print("NO  it is  Present")

Output

Yes it is NOT Present

for i in range (0,5):
  print(i,end=',')

Output

0,1,2,3,4,

url='plus2net.com'
if( '2' in url):
  print("yes 2 is available inside")
else:
  print("No 2 is not available inside ")

Output

yes 2 is available inside

We will use Dictionary

Output depends on Keys of the Dictionary ( Not Values ). If any one of the key present then in returns True otherwise False

my_dict={0:'A',1:'B'}
print(1 in my_dict) # True

my_dict={0:'A',1:'B'}
print('A' in my_dict) # False

my_dict={'A':'X','B':'Y','C':'Z'}
print('X' in my_dict)     # False
print('C' in my_dict)     # True
print('Y' not in my_dict) # True

We will use tuple

my_tuple=(6,1,12,7)
print(7 in my_tuple) # True

my_tuple=(6,1,12,7)
print(8 not in my_tuple) # True