How to round values in a list containing tuples

May 23, 2022

I have a list, which has 2 more lists within it and both of the lists each have 2 tuples in them.

lst = [
  [('Jade', 0.9877607), ('Tom', 0.5728347)],
  [('Jackson', 0.6892309), ('Hazel', 0.6837777)]
]

I want to round all 4 float values to 2 d.p. Would I have to turn each tuple into a list and then change it or is there an easier way to do it?

Thanks!

>Solution :

Since tuples are immutable, you cannot modify them in-place. You’ll need to create a new list based on the current list.

This is very simple to do using a list comprehension:

lst = [
    [('Jade', 0.9877607), ('Tom', 0.5728347)], 
    [('Jackson', 0.6892309), ('Hazel', 0.6837777)],
]

new_list = [
    [(name, round(value, 2)) for (name, value) in sublist]  
    for sublist in lst
]
print(new_list)

# Output:

# [
#    [('Jade', 0.99), ('Tom', 0.57)],
#    [('Jackson', 0.69), ('Hazel', 0.68)]
# ]