如何从列表及其索引中找到最大元素？

Question

I have a list with ordered dictionaries. These ordered dictionaries have different sizes and can also have the same size(for example, 10 dictionaries can have the length of 30 and 20 dictionaries can have the length of 32). I want to find the maximum number of items a dictionary from the list has. I have tried this, which gets me the correct maximum length:

maximum_len= max(len(dictionary_item) for dictionary_item in item_list)

But how can I find the dictionary fields for which the maximum_len is given? Say that the maximum_len is 30, I want to also have the dictionary with the 30 keys printed. It can be any dictionary with the size 30, not a specific one. I just need the keys of that dictionary.

Answer 1

Well you can always use filter:

output_dics=filter((lambda x: len(x)==maximum_len),item_list)

then you have all the dictionarys that satisfies the condition, pick a random one or the first one

Answer 2

Don't know if this is the easiest or most elegant way to do it but you could just write a simple function that returns 2 values, the max_length you already calculated but also the dict that you can get via the.index method and the max_length of the object you were searching for.

im talking about something like this:

    def get_max(list_of_dict):
        plot = []
        for dict_index, dictionary in enumerate(list_of_dict):
            plot.append(len(dictionary))

        return max(plot), list_of_dict[plot.index(max(plot))]

    maximum_len, max_dict = get_max(test)

tested it, works for my case, although i have just made myself a testlist with just 5 dicts of different length.

EDIT: changed variable "dict" to "dictionary" to prevent it shadowing from outer scope.