printing out duplicates based on count in a list of list Python

Question

I want to separate out strings(names) that repeat three or more times in a list and store them in a separate list

List:

[['jane','michael','david','Kieran','steven'],['peter','Ivan','michael','michael','Kieran'],['jane','michael','andrea','anthony','david'],
['michael','Kieran','Martinez','david','Courtney']]

Expected Output(New List):

['michael','kieran','david']

Answer 1

try this, Counter + chain.from_iterable

from collections import Counter
from itertools import chain

print([k for k,v in Counter(chain.from_iterable(values)).items() if v >= 3])

---

['michael', 'david', 'Kieran']

Answer 2

you can use a for loop to iterate the list and store the duplicates in a dict and separate based on count

new_list=[]
dicta={}
for i in a:
    for j in i:
        if j in dicta:
            dicta[j]+=1
        else:
            dicta[j]=1            
for i in dicta.keys():
    if dicta[i]>=3 :
        new_list.append(i)

Answer 3

You first needs to create a new list of names where you could iterate over to generate the new list

source = [['jane','michael','david','Kieran','steven'],['peter','Ivan','michael','michael','Kieran'],['jane','michael','andrea','anthony','david'],['michael','Kieran','Martinez','david','Courtney']]


new_names_list = []
for names in source :
    for n in names:
        new_names_list.append(n)

print(new_names_list) ## this is the new list of names derived from your source

New you could use Counter to derive the count list

from collections import Counter
counter_name_dict = Counter(new_names_list)

result = []
for k, v in counter_name_dict.items():
    if v >= 3:
       result.append(k)

The result will now only hold the list of names which are having a count of 3 or more.

Answer 4

This is one solution:

from collections import defaultdict

lists = [['jane','michael','david','Kieran','steven'],['peter','Ivan','michael','michael','Kieran'],['jane','michael','andrea','anthony','david'],
['michael','Kieran','Martinez','david','Courtney']]

d = defaultdict(lambda: 0)
for l in lists:
  for e in l:
    d[e] += 1

results = [key for key in d if d[key] >= 3]

Answer 5

Here's an example code:

import collections

thelist = [['jane','michael','david','Kieran','steven'],['peter','Ivan','michael','michael','Kieran'],['jane','michael','andrea','anthony','david'],
['michael','Kieran','Martinez','david','Courtney']]

counts = {}

for l in thelist:
    print(collections.Counter(l))
    for key,value in collections.Counter(l).items():
        if key in counts:
            counts[key] += value
        else:
            counts[key] = value
newlist = []
for key,value in counts.items():
    if value == 3:
        newlist.append(key)