Set

pantry = {"Flour", "Sugar", "Eggs", "Milk", "Butter"}

Practices

1. Removing duplications

    recipe_ingredients_array = ["Flour", "Sugar", "Eggs", "Milk", "Butter", "Sugar"]
    unique_ingredients_set = set(recipe_ingredients_array)
   

2. Set operations

    pantry = {"Flour", "Sugar", "Eggs", "Milk", "Butter"}
    recipe = {"Sugar", "Eggs", "Chocolate", "Butter"}
   
    shopping_list = recipe - pantry
   

3. Efficient membership testing

    time python3 -c "data = list(range(1000000)); membership_checks = [i in data for i in range(10000)]"
   

Recipe: Things that are sets

I noticed that I underestimate the power of sets. Here are some examples where using a set makes sense:

• book genres
• tags for a blog post
• ingredients for a recipe
• user permissions
• available colors for a palette
• playing card suits

If you see any of this:

• genre
• category
• tag
• feature
• unique

There is a chance that representing as a set can help.