Python | Get key from value in Dictionary
Let’s see how to get the key by value in Python Dictionary.
Method 1: Using list.index()
The index() method returns index of corresponding value in a list. Below is an implementation how to use index() method to fetch Dictionary key using value.
Python3
# creating a new dictionarymy_dict ={"java":100, "python":112, "c":11}# list out keys and values separatelykey_list = list(my_dict.keys())val_list = list(my_dict.values())# print key with val 100position = val_list.index(100)print(key_list[position])# print key with val 112position = val_list.index(112)print(key_list[position])# one-linerprint(list(my_dict.keys())[list(my_dict.values()).index(112)]) |
java python python
Explanation:
The approach used here is to find two separate lists of keys and values. Then fetch the key using the position of the value in the val_list. As key at any position N in key_list will have corresponding value at position N in val_list.
Method #2: Using dict.item()
We can also fetch key from a value by matching all the values and then print the corresponding key to given value.
Python3
# function to return key for any valuedef get_key(val): for key, value in my_dict.items(): if val == value: return key return "key doesn't exist"# Driver Codemy_dict ={"java":100, "python":112, "c":11}print(get_key(100))print(get_key(11)) |
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