insert both key and value in dictionary in python by R4R Team

- setdefault() is a python dictionary function which insert key and their value simultaneously in the dictionary.

Syntax-

dict.setdefault(key,value)

- Here dict is actual dictionary in which we want to insert data.
- Key is mendatory
- Value is optional, by default it is None.

Example-

dictionary is d={1:'a',2:'b'}
d.setdefault(3,'c') will return {1:'a',2:'b',3:'c'}


program-

d=dict()
print("Enter key and value in dictionary")
d.setdefault(input(),input())

print("Dictionary is",d)

d.setdefault(2,'b')
print("Dictionary is",d)

d.setdefault(3)
print("Dictionary is",d)

d.setdefault(4,'text')
print("Dictionary is",d)

d.setdefault(5,[6,7,8])
print("Dictionary is",d)

output-

Enter key and value in dictionary
1
one
Dictionary is {'1': 'one'}
Dictionary is {'1': 'one', 2: 'b'}
Dictionary is {'1': 'one', 2: 'b', 3: None}
Dictionary is {'1': 'one', 2: 'b', 3: None, 4: 'text'}
Dictionary is {'1': 'one', 2: 'b', 3: None, 4: 'text', 5: [6, 7, 8]}

-In this program, initially we have a empty dictionary by d=dict() then first data we put by input() function,
-then using setdefault() function e insert new keys and values in the dictionary.
- In d.setfault(3), there is only one argument given so it compute as a key and default value is None, so will print 3:None.