打印一个包含最多 n 个重复元素的列表

Question

To sum up I need to do create a function that receives a list as an input and a number N and returns a new list that contains each repeated element on the maximum of n times

Here is an example:

def reduceList(L,n):
    newList = []
    n = int(input('how many times?'))
    for i in L:
        if i not in L:
            newList.append(i)
    newList.sort()
    return L

lisca = [1, 2, 3, 2, 5, 6, 7, 2, 1, 7, 1, 7]
lisca = reduceList(lisca)
print(lisca)

Answer 1

one solution would be as follows:

def reduceList(oldList: list, numberOfRepeats: int):
    newList = []
    for item in oldList:
        if newList.count(item) < numberOfRepeats:
            newList.append(item)
    newList.sort()
    return newList

good luck!

Answer 2

Using Counter to create a dictonary where the key is an item in list and the value is the occurence, the main wrapper:

lisca=  [1, 2, 3, 2, 5, 6, 7, 2, 1, 7, 1, 7]
occurence_dict = Counter(lisca)
Counter({1: 3, 2: 3, 7: 3, 3: 1, 5: 1, 6: 1})
lisca = parse_list(lisca,2)
occurence_dict = Counter(lisca)
Counter({1: 2, 2: 2, 7: 2, 3: 1, 5: 1, 6: 1})

The function code:

from collections import Counter
def parse_list(L,n):
    result_list = []
    occurence_dict = Counter(L)
    for key, counter in occurence_dict.items():
        if counter <= n:
            result_list.extend([key for i in range(counter)])
        else:
            result_list.extend([key for i in range(n)])
    return result_list