我如何将 append 与所需值相对应的键添加到 Python 中的列表？

Question

I have a dictionary that has, for example, {1: apple, 2:orange, 3:pear, 4:apple, etc.} where the value 'apple' is repeated for different key integers (such as the keys 1, 4, 7, 9, and 21 all have the value apple in my dictionary). I have a loop that searches the dictionary for the value 'apple', but I want the keys (1, 4, 7, 9, 21, etc.) associated with the value to be appended to a new list called "Apple Numbers" (and just the keys, not the value 'apple'). However, I do not know how to do this.

I am a beginner, so my apologies for such a basic question. Also, this is just an example as this is not the actual problem I need help solving with apples and fruits; I just need help understanding the concept of how to do this so I can apply it to the project I am working on!

Thanks in advance: :)

Answer 1

The basic gist is

my_apples = []
for key, value in dictionary.items():
    if value == "apple":
        my_apples.append(key)

A more fluent approach would be to use a comprehension:

my_apples = [key for key, value in dictionary.items() if value == "apple"]