Python Program for Dictionary setdefault() Method

In the previous article, we have discussed Python Program for floor() Function
Dictionary in python :

A dictionary is a set of elements that have key-value pairs. The values in the elements are accessed using the element’s keys.

Examples:

Example1:

Input:

Given dictionary = {'hello': 25, 'this': 35, 'is': 45, 'btechgeeks': 55}

Output:

The above given dictionary is :
{'hello': 25, 'this': 35, 'is': 45, 'btechgeeks': 55}
The value at the given key hello =  25
The value at the given key btechgeeks=  55
The value at the given key good =  None
The value at the given key morning =  None

Example2:

Input:

Given dictionary = {100: 'good', 150: 'morning', 200: 'btechgeeks'}

Output:

The above given dictionary is :
{100: 'good', 150: 'morning', 200: 'btechgeeks'}
The value at the given key 200 =  btechgeeks
The value at the given key 10 =  None
The value at the given key 150 =  morning

Program for Dictionary setdefault() Method in Python

Using Built-in Functions (Static Input)
Using Built-in Functions (User Input)

Dictionary setdefault() Function:

The Python Dictionary setdefault() function is one of several Dictionary functions that can be used to print the value at a specific key position. It prints None if there is no value at the given index.

Syntax:

dictionary.setdefault(keyname, value)

Parameter values:

Keyname: This is required.The keyname of the item from which you want to retrieve the value.

Value: This is optional. This parameter has no effect if the key exists. If the key does not exist, this value takes its place. The default value is None.

Method #1: Using Built-in Functions (Static Input)

Approach:

Give the dictionary as static input by initializing it with some random values and store it in a variable.
Print the above-given dictionary.
Apply dictionary.setdefault() method to the above-given dictionary to print the value at a specific key position and print it.
It prints None if there is no value at the given index.
Similarly, do the same for the other keys and print them.
The Exit of Program.

Below is the implementation:

# Give the dictionary by initializing it with some random values and store it
# in a variable.
gvn_dictinry = {'hello': 25, 'this': 35, 'is': 45, 'btechgeeks': 55}
# Print the above-given dictionary.
print("The above given dictionary is :")
print(gvn_dictinry)
# Apply dictionary.setdefault() method to the above-given dictionary to print the
# value at a specific key position and print it.
# It prints None if there is no value at the given index.
print("The value at the given key hello = ",
      gvn_dictinry.setdefault('hello', None))
# similarly do the same for the other keys and print them.
print("The value at the given key btechgeeks= ",
      gvn_dictinry.setdefault('btechgeeks', None))
print("The value at the given key good = ",
      gvn_dictinry.setdefault('good', None))
print("The value at the given key morning = ",
      gvn_dictinry.setdefault('morning', None))

Output:

The above given dictionary is :
{'hello': 25, 'this': 35, 'is': 45, 'btechgeeks': 55}
The value at the given key hello =  25
The value at the given key btechgeeks=  55
The value at the given key good =  None
The value at the given key morning =  None

Method #2: Using Built-in Functions (User Input)

Approach:

Take a dictionary and initialize it with an empty dictionary using dict() or {}.
Give the number of keys as user input using int(input()) and store it in a variable.
Loop till the given number of keys using for loop.
Inside the for loop scan the key and value as user input using input(), split() functions, and store them in two separate variables.
Initialize the key with the value of the dictionary.
Print the above-given dictionary.
Give the key that you want to fetch the value as user input using the input() function and store it in another variable.
Apply dictionary.setdefault() method to the above-given dictionary to print the value at a specific key position and print it.
It prints None if there is no value at the given index.
Similarly, do the same for the other keys and print them.
The Exit of Program.

Below is the implementation:

# Take a dictionary and initialize it with an empty dictionary using dict() or {}.
gvn_dictinry = {}
# Give the number of keys as user input using int(input()) and store it in a variable.
numb_of_kys = int(
    input('Enter some random number of keys of the dictionary = '))
# Loop till the given number of keys using for loop.
for p in range(numb_of_kys):
        # Inside the for loop scan the key and value as
    # user input using input(),split() functions
    # and store them in two separate variables.
    keyy, valuee =  input(
        'Enter key and value separated by spaces = ').split()
    # Initialize the key with the value of the dictionary.
    gvn_dictinry[keyy] = valuee

# Print the above-given dictionary.
print("The above given dictionary is :")
print(gvn_dictinry)
# Give the key that you want to fetch the value as user input using the input()
# function and store it in another variable.
gvn_key1 = input("Enter some random number = ")
# Apply dictionary.setdefault() method to the above-given dictionary to print the
# value at a given specific key position and print it.
# It prints None if there is no value at the given index.
print("The value at the given key", gvn_key1, " = ",
      gvn_dictinry.setdefault(gvn_key1, None))
# similarly do the same for the other keys and print them.
gvn_key2 = input("Enter some random number = ")
print("The value at the given key", gvn_key2, " = ",
      gvn_dictinry.setdefault(gvn_key2, None))

Output:

Enter some random number of keys of the dictionary = 3
Enter key and value separated by spaces = 20 good
Enter key and value separated by spaces = 40 morning
Enter key and value separated by spaces = 60 btechgeeks
The above given dictionary is :
{'20': 'good', '40': 'morning', '60': 'btechgeeks'}
Enter some random number = 40
The value at the given key 40 = morning
Enter some random number = 100
The value at the given key 100 = None

Learn several Python Dictionary Method Examples on our page and access the dictionary items easily.