嵌套if进入python中的嵌套for

Question

我正在为一家汉堡店用 Python 开发一个应用程序 web，这个应用程序将从数据库中获取一些数据，我需要管理这些数据

从数据库中我会得到一个元组列表，就像这个一样 check_table = [(1,'Classic', 'Cheddar', 'medium'), (2,'Big', 'Cheddar', 'rare'), (3,'Classic', 'Cheddar', 'rare') ]

在这里，我尝试根据牛排的烹饪水平获得适当数量的牛排，如稀有、中等、熟透

我花了很多时间，但我没有让代码正确计数，我什至试图做出类似的陈述

如果 check_table[x][y] == "经典" 和 check_table[x][y] == "稀有"：

牛排 += 1 稀有 +=1

代码如下：

check_table = [(1,'Classic', 'Cheddar', 'Medium'), (2,'Big', 'Cheddar', 'Rare'), (3,'Classic', 'Cheddar', 'Rare')]

# Variables
steaks = 0
rare = 0
medium = 0
w_done = 0

# Getting all the data from a nested for
for x in range(len(check_table)):
    for y in range(len(check_table[0])):
        # Getting the number of steaks
        if check_table[x][y] == "Classic":
            steaks += 1
            # Getting the style of the steak
            if check_table[x][y] == "Rare":
                rare += 1
            elif check_table[x][y] == 'Medium':
                medium += 1
            elif check_table[x][y] == 'Well-done':
                w_done += 1

        elif check_table[x][y] == "Big":
            steaks += 2
            # Getting steak style
            if check_table[x][y] == 'Rare':
                rare += 2
            elif check_table[x][y] == 'Medium':
                medium += 2
            elif check_table[x][y] == 'Well-done':
                w_done += 2

print("# Steaks ", steaks)
print("# Rare ", rare)
print("# Medium ", medium )
print("# Well-done ", w_done)

我希望得到这样的东西 牛排 4 稀有 3 中等 1 干得好 0

因为经典汉堡包含一块牛排，而大汉堡包含两块牛排，所以我得到了这个，就像 if 语句不存在一样

牛排 4 稀有 0 中 0 干得好 0

希望有人能帮我解决这个问题，谢谢大家

Answer 1

check_table = [(1,'Classic', 'Cheddar', 'Medium'), (2,'Big', 'Cheddar', 'Rare'), (3,'Classic', 'Cheddar', 'Rare')]

# Variables
steaks = 0
rare = 0
medium = 0
w_done = 0

# Getting all the data from a nested for
for x in check_table:
    print(x)
      # Getting the number of steaks
    if x[1] == "Classic":
        steaks += 1
          # Getting the style of the steak
        if x[3] == "Rare":
            rare += 1
        elif x[3] == 'Medium':
            medium += 1
        elif x[3] == 'Well-done':
            w_done += 1

    elif x[1] == "Big":
        steaks += 2
          # Getting steak style
        if x[3] == 'Rare':
            rare += 2
        elif x[3] == 'Medium':
            medium += 2
        elif x[3] == 'Well-done':
            w_done += 2

print("# Steaks ", steaks)
print("# Rare ", rare)
print("# Medium ", medium )
print("# Well-done ", w_done)

Answer 2

您应该尝试将所有这些if/elif 语句转换为对某些数据结构的查找。它会让一切更容易推理，更容易编辑，它会让你的代码更加简洁。

例如，不要使用 if/elif 检查有多少牛排，而只需查找经典与大牛排有多少：

steak_count = {
    'Classic': 1,
    'Big': 2
}
count = steak_count['Big'] # 2 steaks for 'Big'

现在，如果您添加不同种类的汉堡，您无需再次编写一整套 if/elif 语句。您可以通过以下方式将这个想法传达给其他人：

check_table = [(1,'Classic', 'Cheddar', 'Medium'), (2,'Big', 'Cheddar', 'Rare'), (3,'Classic', 'Cheddar', 'Rare')]

steak_count = {
    'classic': 1,
    'big': 2
}
# Variables
counts = {
    'steaks': 0,
    'rare': 0,
    'medium': 0,
    'w_done': 0  
}

for order_num, steak, cheese, cooked in check_table:
    count = steak_count[steak.lower()]
    counts['steaks'] += count
    counts[cooked.lower()] += count

print(counts)
# {'steaks': 4, 'rare': 3, 'medium': 1, 'w_done': 0}