Python Program – Create dictionary from the list

When it is required to create a dictionary from a list, a dictionary is created using ‘dict’ method, a simple iteration and the ‘setdefault’ method is used.

Example

Below is a demonstration of the same −

my_dict = dict()
print("An empty dictionary has been created")
my_value_list = ['15', '14', '13', '12', '16']

print("The list is : " )
print(my_value_list)

my_value_list.sort()
print("The list after sorting is :")
print(my_value_list)

for value in my_value_list:
   for element in range(int(value), int(value) + 2):
      my_dict.setdefault(element, []).append(value)

print("The resultant dictionary is : ")
print(my_dict)

Output

An empty dictionary has been created
The list is :
['15', '14', '13', '12', '16']
The list after sorting is :
['12', '13', '14', '15', '16']
The resultant dictionary is :
{12: ['12'], 13: ['12', '13'], 14: ['13', '14'], 15: ['14', '15'], 16: ['15', '16'], 17: ['16']}

Explanation

• An empty dictionary is created.

• A list is defined and is displayed on the console.

• The list is sorted using a sort method and is displayed on the console.

• The list is iterated over, and the default value is added to the empty dictionary, and the value is also appended to the dictionary.

• This is assigned to a result.

• This is displayed as output on the console.