Given a list of lists, the task is to find the count of unique sublists within list. Examples:
Input: [['Geek', 'for', 'geeks'], ['geeks', 'for'],
['for', 'Geeks', 'geek'], ['Geek', 'for', 'geeks']]
Output:
{('geeks', 'for'): 1, ('for', 'Geeks', 'geek'): 1,
('Geek', 'for', 'geeks'): 2}
Below are some ways to achieve the task. Method #1: Using Iteration
# Python code to count unique sublist within list
# Input list initialization
Input = [['Geek', 'for', 'geeks'], ['geeks', 'for'],
['for', 'Geeks', 'geek'], ['Geek', 'for', 'geeks']]
# Output list initialization
Output = {}
# Using Iteration
for lis in Input:
Output.setdefault(tuple(lis), list()).append(1)
for a, b in Output.items():
Output[a] = sum(b)
# Printing output
print(Output)
Output:
{('Geek', 'for', 'geeks'): 2, ('geeks', 'for'): 1, ('for', 'Geeks', 'geek'): 1}
Time Complexity: O(n)
Auxiliary Space: O(n)
Method #2: Using Counter
# Python code to find count of unique list in list of list
# Importing counter from collection
from collections import Counter
# Input list initialization
lst = [[1, 2, 3], [4, 5, 6], [3, 2, 1], [1, 2, 3]]
# Using counter
Output = Counter([tuple(i) for i in lst])
# Printing output
print(Output)
Output:
Counter({(1, 2, 3): 2, (3, 2, 1): 1, (4, 5, 6): 1})Time Complexity: O(n), where n is the number of elements in the list “test_list”.
Auxiliary Space: O(1), constant space needed
Method #3: Using Pandas
# Python code to count unique sublist within list
# Importing
from collections import Counter
import pandas as pd
# Input list initialization
lst = [[1, 2, 3], [4, 5, 6], [3, 2, 1], [1, 2, 3]]
# Getting count
dict = Counter([tuple(i) for i in lst])
# Creating pandas dataframe
Output = pd.DataFrame(data ={'list': list(dict.keys()),
'count': list(dict.values())})
# Printing output
print(Output)
Output:
count list 0 1 (3, 2, 1) 1 1 (4, 5, 6) 2 2 (1, 2, 3)
Time Complexity: O(n), where n is the length of the list
Auxiliary Space: O(n) additional space of size n is created where n is the number of elements in the list
