Sort variables into their own category-CodePudding

If I have two set of lists and I want them to be sorted into their categories. eg. if i have two list like below

x = ["fruits", "vegetables", "fruits", "meat"]
y = ["apples", "cabbage", "banana", "beef"]

and I want them to output like this

> fruits
       apples
       banana
  vegetables
       cabbage
  meat
       beef

how do i do it?

CodePudding user response：

I'd create a defaultdict with an empty list as the default item, and then iterate over the two lists (e.g., using zip) and append each item of y to the appropriate x:

result = defaultdict(list)
for z in zip(x,y):
    result[z[0]].append(z[1])

CodePudding user response：

You can do this with groupby:

import itertools

# Group
for categroy, items in itertools.groupby(
        # groupby requires it to be sorted
        sorted(
            # combine the adjacent elements of both loops
            zip(x,y)),
        # group by the first element
        key=lambda i:i[0]):
    # print the category
    print(category)
    for item in items:
         # print the item
         print(f"\t{item[1]}")