如何在列表中包含字符串或“和”？

Question

所以在我的代码中我想做这个结构

将 、 、 和 混合在一起。

我有这个代码

import random

ingredient = ['flour', 'baking powder', 'butter', 'milk', 'eggs', 'vanilla', 'sugar']

def create_recipe(main_ingredient, baking, measure, ingredient):
    """Create a random recipe and print it."""
    m_ingredient = random.choice(main_ingredient) #random choice from the main ingredient
    baking_ = random.choice(baking) #random choice from the baking list
    ingredients = random.choice(ingredient) #random choice from the ingredient list

    print("***", m_ingredient.title(), baking_.title() , "Recipe ***")
    print("Ingredients:")
    print(random.randint(1,3), random.choice(measure), m_ingredient)
    for i in range(len(ingredients)): #get the random ingredients
        print(random.randint(1,3), random.choice(measure), ingredient[i])
    print ("Method:")

    selected=[] # this is where the ingredients from the recipe
    selected_items = "Mix the"
    for i in range(len(ingredients)):
        ingredients= str(random.choice(ingredient))
        selected.append(ingredients)
    selected.insert(-2,'and')
    print(selected_items,",".join(selected), "together.") 

我有这个作为它的输出。

将鸡蛋、发酵粉、糖和面粉、糖混合在一起。

如何在列表中的最后一项之前添加“和”并使其与我想要的结构一样？

Answer 1

将所有成分放入列表并根据您选择的字符串格式对其进行切片：

things = ['flour', 'baking powder', 'butter', 'milk', 'eggs', 'vanilla', 'sugar']

# join all but the last element using ", " as seperator, then print the last element
# after the "and"    
print(f"You need {', '.join(things[:-1])} and {things[-1]}")

# or

print("You need", ', '.join(things[:-1]), "and", things[-1])

输出：

You need flour, baking powder, butter, milk, eggs, vanilla and sugar

更多资源：

• Understanding slice notation
• Is there a Python equivalent to Ruby's string interpolation?
• Joining pairs of elements of a list - Python（相关，或许更好用