如何从用户传递多个值并在字典中搜索它们以返回键

Question

我有这本词典：

sales = {
    "January": 15000, "February": 22000, "March": 12000,
    "April": 17000, "May": 81000, "June": 13000,
    "July": 21000, "August": 41200, "September": 25000,
    "October": 21500, "November": 91000, "December": 21000
}

我希望用户能够输入任意数量的值，然后根据输入的值打印一个或多个键，如果该值不在字典中，则必须返回“未找到” ”。

我试过用这个：

search = int(sys.argv[1])
sales_inv = {v: k for k, v in sales.items()}
if search in sales.values():
    for key, value in sales.items():
        if search == value:
            print(key)
else:
    print("not found")

但是当我打印时，它只会搜索一个值，如果我想搜索例如：17000 和 13000，它只会返回“April”。

Answer 1

我认为要获取多个参数，您可以从索引 1 开始遍历 sys.argv，而不是只获取 sys.argv[1]，这只会给出第二个参数值

import sys

sales = {
"January": 15000, "February": 22000, "March": 12000, "April": 17000, "May": 81000, "June": 13000, "July": 21000, "August": 41200,"September": 25000, "October": 21500, "November": 91000, "December": 21000}
sales_inv = {v: k for k, v in sales.items()}

for search in sys.argv[1:]:
    search = int(search)
    if search in sales.values():
        for key, value in sales.items():
            if search == value:
                print(key)
    else:
        print("not found")

Answer 2

我强烈建议为此使用argparse 的ArgumentParser。它提供了很多开箱即用的灵活性，例如add_arguments() 的nargs 参数，它允许自动将传递给程序的参数收集到一个列表中。

我会这样做：

from argparse import ArgumentParser

SALES = {
    "January": 15000,
    "February": 22000,
    "March": 12000,
    "April": 17000,
    "May": 81000,
    "June": 13000,
    "July": 21000,
    "August": 41200,
    "September": 25000,
    "October": 21500,
    "November": 91000,
    "December": 21000,
}

parser = ArgumentParser()
parser.add_argument(
    "sales_numbers",

    # Used in help messages.
    metavar="SALES_NUMBER",

    # Convert the input to integer,
    # print an error if non-integer value is passed in.
    type=int,

    # Gather all arguments in a list,
    # print an error if no arguments have been passed in.
    nargs="+",
)
args = parser.parse_args()

# Make the list a set, in case of duplicate input.
sales_numbers = set(args.sales_numbers)

for month, value in SALES.items():
    if value in args.sales_numbers:
        print(month)

# Get a set of numbers that were input but not there.
not_found = sales_numbers - set(SALES.values())

for num in not_found:
    print(f"{num} not found")

您现在可以运行它并传入参数，例如：

$ my_script.py 123
123 not found

$ my_script.py 15000
January

$ my_script.py 21000
July
December

$ my_script.py 21000 15000
January
July
December

$ my_script.py 21000 15000 123 9999
January
July
December
123 not found
9999 not found

如果您忘记传入参数：

$ my_script.py
usage: my_script.py [-h] SALES_NUMBER [SALES_NUMBER ...]
my_script.py: error: the following arguments are required: SALES_NUMBERS

当你传入无法转换为整数的东西时：

$ my_script.py abc
usage: my_script.py [-h] SALES_NUMBER [SALES_NUMBER ...]
my_script.py: error: argument SALES_NUMBER: invalid int value: 'abc'

带有方便的--help 参数：

$ my_script.py --help
usage: sf_args.py [-h] SALES_NUMBER [SALES_NUMBER ...]

positional arguments:
  SALES_NUMBER

optional arguments:
  -h, --help show this help message and exit

Answer 3

好吧，我像往常一样迟到了，但我仍然在这里尝试（值得 10 分钟修改 sys.arg）：

import sys

sales = {"January": 15000, "February": 22000, "March": 12000, "April": 17000, "May": 81000,
         "June": 13000, "July": 21000, "August": 41200,"September": 25000,
         "October": 21500, "November": 91000, "December": 21000}




search = [int(sys.argv[x]) for x in range(1 , len(sys.argv))]


sales_inv = {v: k for k, v in sales.items()}


for i in search:
    if i in sales.values():

        for key, value in sales.items():
    
            if i == value:   

                print(i,' is : ', key)
    else:
    
        print(i,"not found")

它是相同的@user696969，但最愚蠢的版本，使用 argparse 它的冷却器