Question

我正在尝试创建一个卡路里计数器，标准输入如下：

python3 calories.txt < test.txt

在卡路里里面，食物的形式如下：苹果500

我遇到的问题是每当我计算人的价值时，它似乎永远不会返回空列表。

    import sys

food = {}
eaten = {}
finished = {}

total = 0

#mappings 
def calories(x):  
    with open(x,"r") as file:
        for line in file:
            lines = line.strip().split()
            key = " ".join(lines[0:-1])
            value = lines[-1]
            food[key] = value

def calculate(x):
    a = []
    for keys,values in x.items():
        for c in values:
            try:
                a.append(int(food[c]))
            except:
                a.append(100)

    print("before",a)
    a = []
    total = sum(a) # Problem here
    print("after",a)
    print(total) 

def main():
    calories(sys.argv[1])
    for line in sys.stdin:
        lines = line.strip().split(',')
        for c in lines:
            values = lines[0]
            keys = lines[1:]
        eaten[values] = keys
        calculate(eaten)

if __name__ == '__main__':
    main()

编辑 - 忘记包含test.txt的内容：

joe,almonds,almonds,blue cheese,cabbage,mayonnaise,cherry pie,cola
mary,apple pie,avocado,broccoli,butter,danish pastry,lettuce,apple
sandy,zuchini,yogurt,veal,tuna,taco,pumpkin pie,macadamia nuts,brazil nuts
trudy,waffles,waffles,waffles,chicken noodle soup,chocolate chip cookie

Answer 1

如何让自己更轻松：

在阅读卡路里数据时，尽快将卡路里转换为int()，每次想要总结这样的事情时都不需要这样做。字典有一个.get(key, defaultvalue) accessor，所以如果找不到食物，使用100作为默认值是1-liner w / o try: ... except:

这对我有用，不是使用sys.stdin，而是将第二个文件作为文件提供，而不是使用<将其传送到程序中。

我修改了一些解析来删除空格并从calc返回一个[(name,cal),...]元组列表。

它可以帮助您根据自己的喜好进行修复：

def calories(x):  
    with open(x,"r") as file:
        for line in file:
            lines = line.strip().split()
            key = " ".join(lines[0:-1])
            value = lines[-1].strip() # ensure no whitespaces in
            food[key] = int(value)

def getCal(foodlist, defValueUnknown = 100):
    """Get sum / total calories of a list of ingredients, unknown cost 100."""
    return sum( food.get(x,defValueUnknown ) for x in foodlist) # calculate it, if unknown assume 100

def calculate(x):
    a = []
    for name,foods in x.items():
        a.append((name, getCal(foods))) # append as tuple to list for all names/foods eaten
    return a

def main():
    calories(sys.argv[1])
    with open(sys.argv[2]) as f: # parse as file, not piped in via sys.stdin
        for line in f:
            lines = line.strip().split(',')
            for c in lines:
                values = lines[0].strip()
                keys = [x.strip() for x in lines[1:]] # ensure no whitespaces in
                eaten[values] = keys
    calced = calculate(eaten) # calculate after all are read into the dict
    print (calced)

输出：

[('joe', 1400), ('mary', 1400), ('sandy', 1600), ('trudy', 1000)]

使用sys.stdin和管道只是导致我的控制台闪烁并等待手动输入 - 可能VS相关......

永远不会重置列表

1 个答案: