如何在python的for循环中将不同的字典添加到同一列表中？

debugcn 发表于 Dev

CZRM

我正在尝试使用for循环将不同的字典添加到同一列表中，但是我不知道如何在每次迭代中生成新的字典。我使用的文件具有以下格式：
食谱名称
食谱
食谱名称
食谱
，其中食谱是“ 1杯面粉”。有十行食谱

我正在尝试将每个食谱添加到不同的词典，并将这些词典附加到列表中。这是我所拥有的：

    fhand = open("recipe.txt").read()
    lines = fhand.split('\n')
    menu = []
    num_of_ingredients = 10
    count = 0
    d = {}
    for line in lines:
        c = count % (num_of_ingredients + 1)
        if c == 0:
            print("Recipe name: ", line)
            menu.append(d)
        else:
            l = line.split(' ')
            print(l)
            servings = l[0]
            line = line[2::] 
            ingredient = line
            print(servings, str(ingredient)) #this line was for me to know how it looks like
            d[ingredient] = servings
       
        count += 1
    menu.append(d)

索拉迪普·萨哈（Sawradip Saha）

我猜您的文件格式是这样的[如果num_of_ingredients = 3]

Soup
1 cup flour
2 cup ginger 
3 cup onion
Sandwitch
5 cup bread
3 cup meat
8 cup garlic

而你想要的是

[ {"Recipe name": "Soup", "flour":"1 cup", "ginger": "2  cups", "onion":"3 cup"}, ...]

该代码将帮助您：

with open(r"food.txt", "r") as f:
    lines = f.readlines()

num_of_ingredients = 3
menu = []

d = {}  #This defined here just to avoid some warning(d being used before being assigned).

for n_line, line in enumerate(lines): 

    if not ( n_line % (num_of_ingredients+1)):    #enumerate is far better choice than counting manually
        if (n_line != 0) :
            menu.append(d)       #dictionary will be appended , only when it is time to assign a new recipe(but you know that already)
        d = {}               #Here comes the important part(your answer), This is how you should assign new empty dict, everytime a new list item is initiated.
        d["Recipe name"] = line

    else:
        ingredient = ' '.join(line.split()[2:])
        servings = ' '.join(line.split()[:2])
        d[ingredient] = servings
menu.append(d)      #this last append is beacuse after the last iteration, we won't go back to the if block, to append rhe last list item.

print(menu)

如果我的假设有误，请告诉我。

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