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Python: Count number of unique lists within list

Python List: Exercise - 94 with Solution

Write a Python program to count number of unique sublists within a given list.

Sample Solution:

Python Code:

def unique_sublists(input_list):
    result ={}
    for l in input_list: 
        result.setdefault(tuple(l), list()).append(1) 
    for a, b in result.items(): 
        result[a] = sum(b)
    return result

list1 = [[1, 3], [5, 7], [1, 3], [13, 15, 17], [5, 7], [9, 11]] 
print("Original list:")
print(list1)  
print("Number of unique lists of the said list:")
print(unique_sublists(list1)) 

color1 = [["green", "orange"], ["black"], ["green", "orange"], ["white"]]
print("\nOriginal list:")
print(color1)  
print("Number of unique lists of the said list:")
print(unique_sublists(color1))

Sample Output:

Original list:
[[1, 3], [5, 7], [1, 3], [13, 15, 17], [5, 7], [9, 11]]
Number of unique lists of the said list:
{(1, 3): 2, (5, 7): 2, (13, 15, 17): 1, (9, 11): 1}

Original list:
[['green', 'orange'], ['black'], ['green', 'orange'], ['white']]
Number of unique lists of the said list:
{('green', 'orange'): 2, ('black',): 1, ('white',): 1}

Pictorial Presentation:

Python List: Count number of unique lists within list.

Flowchart:

Flowchart: Count number of unique lists within list.

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Previous: Write a Python program to count the number of sublists contain a particular element.
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Python: Tips of the Day

Find current directory and file's directory:

To get the full path to the directory a Python file is contained in, write this in that file:

import os 
dir_path = os.path.dirname(os.path.realpath(__file__))

(Note that the incantation above won't work if you've already used os.chdir() to change your current working directory, since the value of the __file__ constant is relative to the current working directory and is not changed by an os.chdir() call.)

To get the current working directory use

import os
cwd = os.getcwd()

Documentation references for the modules, constants and functions used above:

  • The os and os.path modules.
  • The __file__ constant
  • os.path.realpath(path) (returns "the canonical path of the specified filename, eliminating any symbolic links encountered in the path")
  • os.path.dirname(path) (returns "the directory name of pathname path")
  • os.getcwd() (returns "a string representing the current working directory")
  • os.chdir(path) ("change the current working directory to path")

Ref: https://bit.ly/3fy0R6m