Python – get unique and sorted values in list of lists [closed]

by

Since your question does not clearly state that: This anwer assumes that the entries in all list should be sorted afterwards and that each number is unique within each sublist.

You can reach this as follows:

numbers = [[50, 100],[100, 130],[20, 50, 100, 130]]

unique = sorted({n for l in numbers for n in l})

new_numbers = [[x if x in l else 0 for x in unique] for l in numbers]

new_numbers
> [[0, 50, 100, 0], [0, 0, 100, 130], [20, 50, 100, 130]]

Some explanation on the solution: First, get all (unique) numbers that occur in the original list. Then, go through the original list and add 0 to places, where a number from the unique numbers is not part of the sublist. Note that during this operation, the original list will be sorted, so [100, 50] will become [0, 50, 100, 0].

edit: made more pythonic due to juanpa.arrivillaga’s comment.

More Related Contents:

  1. How are array types (lists and tuples) and for loops related in Python? [closed]
  2. How to map two lists in python? [closed]
  3. How do I concatenate two lists in Python?
  4. How do I clone a list so that it doesn’t change unexpectedly after assignment?
  5. How to sort a list/tuple of lists/tuples by the element at a given index?
  6. How to deep copy a list?
  7. How is Python’s List Implemented?
  8. Permutations between two lists of unequal length
  9. Create an empty list in Python with certain size
  10. Python append() vs. + operator on lists, why do these give different results?
  11. How to zip two differently sized lists, repeating the shorter list?
  12. Python list problem [duplicate]
  13. Calling filter returns [duplicate]
  14. How to sort a list of tuples according to another list
  15. Can I create a “view” on a Python list?
  16. list() uses slightly more memory than list comprehension
  17. Generating sublists using multiplication ( * ) unexpected behavior [duplicate]
  18. Converting Dictionary to List? [duplicate]
  19. Appending to the same list from different processes using multiprocessing
  20. Python AND operator on two boolean lists – how?
  21. How to use python numpy.savetxt to write strings and float number to an ASCII file?
  22. Find an element in a list of tuples
  23. Checking if any elements in one list are in another [duplicate]
  24. How to convert list of tuples to multiple lists?
  25. Print a list in reverse order with range()?
  26. How do I reverse a list using recursion in Python?
  27. python – get list of tuples first index?
  28. Find a value in a list [duplicate]
  29. Creating a list in Python- something sneaky going on?
  30. Rearranging list based on order of another list

Leave a Comment