How to Extract Values from a Dictionary Using a List of Keys?

Retrieving Values from a Dictionary Using a List of Keys

Suppose we have a dictionary mydict containing key-value pairs and a separate list mykeys comprising specific keys from the dictionary. Our goal is to construct a list containing the corresponding values from mydict for the specified keys in mykeys.

Solution: List Comprehension

An efficient approach to achieve this is through list comprehension, which offers a concise and readable solution. Here's how to implement it:

[mydict[x] for x in mykeys]

This code iterates over the mykeys list, accessing each key x within the dictionary mydict. For each key, it retrieves the corresponding value and appends it to the resulting list. For example, given the following dictionary and list of keys:

mydict = {'one': 1, 'two': 2, 'three': 3}
mykeys = ['three', 'one']

The list comprehension would evaluate as follows:

[mydict['three'], mydict['one']]

This results in a list containing the values associated with the keys 'three' and 'one':

[3, 1]

Therefore, using list comprehension provides a straightforward way to extract a list of values from a dictionary based on a given list of keys.

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