Python：根据单独字典中设置的类型，将键与字典中每个键对值的值进行比较

Question

Given two separate example dictionaries:

fruit_type = {'apple': 'stonefruit', 'peach': 'stonefruit', 'pear': 'stonefruit','orange': 'citrus', 'lemon': 'citrus', 'tangerine': 'citrus'}
similar_fruit = {'apple': ['peach', 'pear'], 'peach': ['apple', 'pear'], 'pear': ['apple', 'peach'], 'orange': ['lemon', 'tangerine'], 'lemon': ['orange', 'tangerine'], 'tangerine': ['orange', 'lemon']}

What is the most efficient method of comparing each of the keys against the values in the similar_fruit dictionary based on their values in the other dictionary fruit_type ?

I have what seems like a naive working implementation below:

same_type = False

for fruit in similiar_fruit:
  for comparison in similiar_fruit[fruit]:
    if fruit_type[fruit] == fruit_type[comparison]:
      same_type = True

It might be helpful to note that there are only 2 types of fruits at all times (stonefruit, citrus), and the keys in the first dictionary line up with the keys in the second dictionary in terms of same keys (apple, peach, pear, orange, lemon, tangerine), not necessarily the order of the keys.

Thank you in advance.

Answer 1

I don't believe there is any other way to simplify that! However, I would make the change of starting same_type = True , and make the comparison as:

if fruit_type[fruit] != fruit_type[comparison]:
  same_type = False
  break

That way as soon as a comparison is incorrect, it will fail the inner clause to prevent comparison overwriting, and stop the loop.

Also, if you were looking to simply create a dictionary of each fruit and make a list of which ones they are similar to rather than starting with two dictionaries to compare, I wrote a code to accomplish that here:

fruit_type = {'apple': 'stonefruit', 'peach': 'stonefruit', 'pear': 'stonefruit','orange': 'citrus', 'lemon': 'citrus', 'tangerine': 'citrus'}
similar_fruits = {}

for fruit in fruit_type:
  similar = []
  for comp in fruit_type:
    if fruit != comp:
      if fruit_type[fruit] == fruit_type[comp]:
        similar.append(comp)
  similar_fruits[fruit] = similar

print(similar_fruits)

similar_fruits will then be an automatic dictionary of all fruits and lists of each fruit they are similar to. {'apple': ['peach', 'pear'], 'peach': ['apple', 'pear'], 'pear': ['apple', 'peach'], 'orange': ['lemon', 'tangerine'], 'lemon': ['orange', 'tangerine'], 'tangerine': ['orange', 'lemon']}

Hope this helps! -Nate

Answer 2

Then pair up each fruit with every similar fruit:

similar_pairs = [(f,sim) for f,sims in similar_fruit.items() for sim in sims]

Now ask if both members of the pair are in the same type:

for a,b in similar_pairs:
    if fruit_type[a] == fruit_type[b]:
        print(f"{a} and {b} are similar and the same kind")