Python - Access Dictionary Items

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Using the "[ ]" Operator

A dictionary in Python is not a sequence, as the elements in dictionary are not indexed. Still, you can use the square brackets "[ ]" operator to fetch the value associated with a certain key in the dictionary object.

Example 1

capitals = {"Maharashtra":"Mumbai", "Gujarat":"Gandhinagar", "Telangana":"Hyderabad", "Karnataka":"Bengaluru"}
print ("Capital of Gujarat is : ", capitals['Gujarat'])
print ("Capital of Karnataka is : ", capitals['Karnataka'])

It will produce the following output −

Capital of Gujarat is: Gandhinagar
Capital of Karnataka is: Bengaluru

Example 2

Python raises a KeyError if the key given inside the square brackets is not present in the dictionary object.

capitals = {"Maharashtra":"Mumbai", "Gujarat":"Gandhinagar", "Telangana":"Hyderabad", "Karnataka":"Bengaluru"}
print ("Captial of Haryana is : ", capitals['Haryana'])

It will produce the following output −

   print ("Captial of Haryana is : ", capitals['Haryana'])
                                      ~~~~~~~~^^^^^^^^^^^
KeyError: 'Haryana'

Using the get() Method

The get() method in Python's dict class returns the value mapped to the given key.

Syntax

Val = dict.get("key")

Parameters

• key − An immutable object used as key in the dictionary object

Return Value

The get() method returns the object mapped with the given key.

Example 3

capitals = {"Maharashtra":"Mumbai", "Gujarat":"Gandhinagar", "Telangana":"Hyderabad", "Karnataka":"Bengaluru"}
print ("Capital of Gujarat is: ", capitals.get('Gujarat'))
print ("Capital of Karnataka is: ", capitals.get('Karnataka'))

It will produce the following output −

Capital of Gujarat is: Gandhinagar
Capital of Karnataka is: Bengaluru

Example 4

Unlike the "[]" operator, the get() method doesn't raise error if the key is not found; it return None.

capitals = {"Maharashtra":"Mumbai", "Gujarat":"Gandhinagar", "Telangana":"Hyderabad", "Karnataka":"Bengaluru"}
print ("Capital of Haryana is : ", capitals.get('Haryana'))

It will produce the following output −

Capital of Haryana is : None

Example 5

The get() method accepts an optional string argument. If it is given, and if the key is not found, this string becomes the return value.

capitals = {"Maharashtra":"Mumbai", "Gujarat":"Gandhinagar", "Telangana":"Hyderabad", "Karnataka":"Bengaluru"}
print ("Capital of Haryana is : ", capitals.get('Haryana', 'Not found'))

It will produce the following output −

Capital of Haryana is: Not found