# Python | Increment value in dictionary

• Last Updated : 15 Jan, 2023

Sometimes, while working with dictionaries, we can have a use-case in which we require to increment a particular key’s value in dictionary. It may seem a quite straight forward problem, but catch comes when the existence of a key is not known, hence becomes a 2 step process at times. Let’s discuss certain ways in which this task can be performed.

Method #1 : Using get() The get function can be used to initialize a non-existing key with 0 and then the increment is possible. By this way the problem of non-existing key can be avoided.

## Python3

 `# Python3 code to demonstrate working of``# Increment value in dictionary``# Using get()` `# Initialize dictionary``test_dict ``=` `{``'gfg'` `: ``1``, ``'is'` `: ``2``, ``'for'` `: ``4``, ``'CS'` `: ``5``}` `# printing original dictionary``print``("The original dictionary : " ``+`  `str``(test_dict))` `# Using get()``# Increment value in dictionary``test_dict[``'best'``] ``=` `test_dict.get(``'best'``, ``0``) ``+` `3``    ` `# printing result``print``("Dictionary after the increment of key : " ``+` `str``(test_dict))`

Output :

The original dictionary : {‘is’: 2, ‘CS’: 5, ‘for’: 4, ‘gfg’: 1} Dictionary after the increment of key : {‘is’: 2, ‘CS’: 5, ‘for’: 4, ‘best’: 3, ‘gfg’: 1}

Method #2 : Using defaultdict() This problem can also be solved by using a defaultdict method, which initializes the potential keys and doesn’t throw an exception in case of non-existence of keys.

## Python3

 `# Python3 code to demonstrate working of``# Increment value in dictionary``# Using defaultdict()``from` `collections ``import` `defaultdict` `# Initialize dictionary``test_dict ``=` `defaultdict(``int``)` `# printing original dictionary``print``("The original dictionary : " ``+`  `str``(``dict``(test_dict)))` `# Using defaultdict()``# Increment value in dictionary``test_dict[``'best'``] ``+``=` `3``    ` `# printing result``print``("Dictionary after the increment of key : " ``+` `str``(``dict``(test_dict)))`

Output :

The original dictionary : {} Dictionary after the increment of key : {‘best’: 3}

Method #3 : Using Counter()
Using Counter() is another way to increment the value in dictionary.

## Python3

 `# Python3 code to demonstrate working of``# Increment value in dictionary``# Using Counter()``from` `collections ``import` `Counter``  ` `# Initialize dictionary``test_dict ``=` `{``'gfg'` `: ``1``, ``'is'` `: ``2``, ``'for'` `: ``4``, ``'CS'` `: ``5``}``  ` `# printing original dictionary``print``(``"The original dictionary : "` `+`  `str``(test_dict))``  ` `# Using Counter()``# Increment value in dictionary``val ``=` `Counter(test_dict)``val.update({``'best'``:``3``})``      ` `# printing result``print``(``"Dictionary after the increment of key : "` `+` `str``(``dict``(val)))``#This code is contributed by Edula Vinay Kumar Reddy`

Output

```The original dictionary : {'gfg': 1, 'is': 2, 'for': 4, 'CS': 5}
Dictionary after the increment of key : {'gfg': 1, 'is': 2, 'for': 4, 'CS': 5, 'best': 3}```

Time Complexity : O(1)
Auxiliary Space : O(N)

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