Skip to content
Related Articles

Related Articles

Use get() method to create a dictionary in Python from a list of elements
  • Last Updated : 10 Jul, 2020
GeeksforGeeks - Summer Carnival Banner

Prerequisites: Get() method for dictionaries in Python

The naive approach for creating a dictionary from a list of items we can use the for loop. See the below example for better understanding.

Example:




li =['a', 'b', 'c', 'a', 'd', 'e', 'b', 'a']
di ={}
  
for ele in li:
      
    # Increase the value of key
    # if exists
    if ele in di:
        di[ele]= di[ele]+1
    else:
          
        # Insert the new key:value
        # pair
        di[ele]= 1
  
print(di)

Output:

{'a': 3, 'b': 2, 'c': 1, 'd': 1, 'e': 1}

In the above code, a loop is used to iterate over the elements in the list. If the key is already present in the dictionary, then its value is incremented by 1, else it creates a new key for that element in the dictionary and assigns 1 as a value to it.



An alternative approach that can be used is by using the inbuilt .get() function in the Python library. See the below example for better understanding




li =['a', 'b', 'c', 'a', 'd', 'e', 'b', 'a']
di ={}
  
for ele in li:
    di[ele]= di.get(ele, 0)+1
  
print(di)

Output:

{'a': 3, 'b': 2, 'c': 1, 'd': 1, 'e': 1}

In the above code, a loop is used to iterate over the elements in the list. The code at line 5 creates a key for every element in the list. If the key is already present in the dictionary then, it adds 1 to the value of it, else it creates a new key corresponding to the element and assigns 0 as a default value to it. Then it adds 1 to it to increase the count.

Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course.

My Personal Notes arrow_drop_up
Recommended Articles
Page :