How can optimize below code for counting repeat of each elements in nested of nested list-CodePudding

The code I wrote counts the frequency of each element in a nested list. I have a lot of repeated code. How can I optimize it? I don't want to use built-in function or lib.

Input:

items = [10, "ninety nine", [99, 250, [90, "fifty"], 4.5, [50, 80], 90, "ninety nine"], ["fifty"]]

Output:

{10: 1, 'ninety nine': 2, 99: 1, 250: 1, 90: 2, 'fifty': 2, 4.5: 1, 50: 1, 80: 1}

Code:

items = [10, "ninety nine", [99, 250, [90, "fifty"], 4.5, [50, 80], 90, "ninety nine"], ["fifty"]]

dict1 = dict()


for i in items:
    if isinstance(i, list):
        for j in i:
            if isinstance(j, list):
                for k in j:
                    if k not in dict1:
                        dict1[k] = 1
                    else:
                        dict1[k]  = 1
            else:
                if j in dict1:
                    dict1[j]  = 1
                else:
                    dict1[j] = 1

    else:
        if i in dict1:
            dict1[i]  = 1
        else:
            dict1[i] = 1


print(dict1)

Any suggestions would be greatly appreciated.

CodePudding user response：

You can use recursion to flatten the list and then count specific items:

items = [
    10,
    "ninety nine",
    [99, 250, [90, "fifty"], 4.5, [50, 80], 90, "ninety nine"],
    ["fifty"],
]


def get_items(v):
    if isinstance(v, list):
        for i in v:
            yield from get_items(i)
    else:
        yield v


cnt = {}
for i in get_items(items):
    cnt[i] = cnt.get(i, 0)   1

print(cnt)

Prints:

{
    10: 1,
    "ninety nine": 2,
    99: 1,
    250: 1,
    90: 2,
    "fifty": 2,
    4.5: 1,
    50: 1,
    80: 1,
}

CodePudding user response：

You can write a recursive function to flatten your nested list then use Collection.Counter to get the count of each element.

from collections import Counter

items = [10, "ninety nine", [99, 250, [90, "fifty"], 4.5, [50, 80], 
                             90, "ninety nine"], ["fifty"]]

def flatten_list(items, lst):
    for item in items:
        if isinstance(item , list):
            flatten_list(item, lst)
        else:
            lst  = [item]
    return lst

res = flatten_list(items, [])
print(dict(Counter(res)))

{10: 1, 'ninety nine': 2, 99: 1, 250: 1, 90: 2, 'fifty': 2, 4.5: 1, 50: 1, 80: 1}