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pythonstringdictionarycomparison

Python: Comparing dictionary key with string


I'm trying to compare the key in a dictionary with a string in Python but I can't find any way of doing this. Let's say I have:

dict = {"a" : 1, "b" : 2}

And I want to compare the key of the first index in the dictionary (which is "a") with with a string. So something like:

if ´Dictionary key´ == "a":
    return True
else:
    return False

Is there a way of doing this? Appreciate all the help I can get.


Solution

  • Python dictionnaries have keys and values accessed using those keys.

    You can access the keys as follows, your dict key will be stored in the key variable:

    my_dict = {"a" : 1, "b" : 2}
    for key in my_dict:
        print(key)
    

    This will print:

    a
    b
    

    You can then do any comparisons you want:

    my_dict = {"a" : 1, "b" : 2}
    for key in my_dict:
        if key == "a":
            return True
        else:
            return False
    

    which can be improved to:

    my_dict = {"a" : 1, "b" : 2}
    print("a" in my_dict.keys())
    

    You can then access the values for each key in your dict as follows:

    my_dict = {"a" : 1, "b" : 2}
    for key in my_dict:
        print(my_dict[key])
    

    This will print:

    1
    2
    

    I suggest you read more about dictionaries from the official Python documentation: https://docs.python.org/3.6/tutorial/datastructures.html#dictionaries