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Hello Pythonistas, welcome back.

Today we will see different ways of extracting values and keys from a python dictionary.

How to extract value from a Python dictionary using key?

Let’s say your friend comes to your shop to buy an apple🍎. Then you search in your dict where’s my apple this way:-

where_is_what = {"apple": "top row of shelf",
"banana": "bottom row of the shelf",
"spinach": "middle row of the shelf"}
print(where_is_what['apple'])

Output:-

top row of shelf

You can make results look even more clear using an f-string:

print(f"Where's my apple? It is in the:- {where_is_what['apple']}")

Output:-

Where's my apple? It is in the:- top row of shelf

Similarly, you can easily access any other item’s location.

It’s been a month and you are making great progress in the store and decided to expand your product line and make a few changes. Let’s do them.

Time ⌚ to take a look at some amazing functions/methods on dictionaries.

How to extract all values from a dictionary in Python?

In case you wish to extract all the values from the dictionary you can use the values() method:

where_is_what = {"apple": "top row of shelf",
"banana": "bottom row of the shelf",
"spinach": "middle row of the shelf"}
print(where_is_what.values())

Output:-

dict_values(['top row of shelf', 'bottom row of the shelf', 'middle row of the shelf'])

How do you print all the keys from a dictionary in Python?

If you want to know what items are there in your shop (you want to access all the keys) then, you can use the keys() method:

where_is_what = {"apple": "top row of shelf",
"banana": "bottom row of the shelf",
"spinach": "middle row of the shelf"}
print(where_is_what.keys())

Output:-

dict_keys(['apple', 'banana', 'spinach'])

How to get key by value in a Python dictionary?

Although Python offers no such method you can use any of these 3 tricks:

1. for Loop

Step1: Store the value(whose key you want)

value = "top row of shelf"

Step2: Run a loop

for key, val in where_is_what:
    if(val == value):
        req_key = key
        
#the key we wanted
print(key)

Output:

apple

2. Lists

1. Get the keys (using .keys())
2. Get the values (using .values())
3. Get the index of the value you want (index(val) of list)
4. Get the same index from the key list. (key_lst[index])

3. List Comprehension

You just repeat the first method but write it in a crisp manner:

value = "top row of shelf"

req_key = [key for key, val in items if val == value]  
print(f"The key of {value} in the dictionary is: ", req_key)  

Output:

apple