Find the sum of two lists of lists element-wise [closed]

by

You could just use zip like,

>>> list1
[[1, 2, 3], [4, 5, 6]]
>>> list2
[[10, 2, 3], [11, 5, 6]]
>>> [[x+y for x,y in zip(l1, l2)] for l1,l2 in zip(list1,list2)]
[[11, 4, 6], [15, 10, 12]]

or if you are not sure, if both list will be of same length, then you can use zip_longest (izip_longest in python2) from itertools and use the fillvalue like,

>>> import itertools
>>> y = itertools.zip_longest([1,2], [3,4,5], fillvalue=0)
>>> list(y)
[(1, 3), (2, 4), (0, 5)]

that then you can use it for unequal sized data like,

>>> from itertools import zip_longest
>>> list1=[[1, 2, 3], [4, 5]]
>>> list2=[[10, 2, 3], [11, 5, 6], [1,2,3]]
>>> [[x+y for x,y in zip_longest(l1, l2, fillvalue=0)] for l1,l2 in zip_longest(list1,list2, fillvalue=[])]
[[11, 4, 6], [15, 10, 6], [1, 2, 3]]

More Related Contents:

  1. How to find the cumulative sum of numbers in a list?
  2. List comprehension on a nested list?
  3. Extract first item of each sublist
  4. Sum a list of numbers in Python
  5. Finding max value in the second column of a nested list?
  6. Add SUM of values of two LISTS into new LIST
  7. Sum of list of lists; returns sum list
  8. Summing elements in a list
  9. Generate all possible lists of length N that sum to S in Python
  10. Comprehension on a nested iterables?
  11. Flattening a list recursively [duplicate]
  12. How can I use list comprehensions to process a nested list?
  13. Turning a list into nested lists in python
  14. Counting depth or the deepest level a nested list goes to
  15. How to zip two lists of lists
  16. Python3 – create global variable(list) from function
  17. In Python, what is the difference between “.append()” and “+= []”?
  18. a mutable type inside an immutable container
  19. Different ways of clearing lists
  20. How to get item’s position in a list?
  21. Complexity of list.index(x) in Python
  22. How to transform string of space-separated key,value pairs of unique words into a dict
  23. Nested list comprehensions
  24. How can I format a list to print each element on a separate line in python? [duplicate]
  25. Group list by values [duplicate]
  26. What are dict_keys, dict_items and dict_values?
  27. Ordered intersection of two lists in Python
  28. What to consider before subclassing list?
  29. How does str.startswith really work?
  30. Best way to remove elements from a list

Leave a Comment