在 json 对象的嵌套字典中查找项目

Question

我正在尝试将 json 对象作为输入，并找到符合特定条件的项目数。 json 对象结构在嵌套的 python 字典中，例如：

businesses= ["{\"hours\":
            {
            \"tuesday\": [[\"11:30\", \"23:00\"]],
            \"thursday\": [[\"11:30\", \"23:00\"]],
            \"wednesday\": [[\"11:30\", \"23:00\"]],
            \"friday\": [[\"11:30\", \"23:00\"]],
            \"sunday\": [[\"9:00\", \"23:00\"]],
            \"monday\": [[\"11:30\", \"23:00\"]],
            \"saturday\": [[\"11:30\", \"23:00\"]]
            },
            \"name\": \"XYZ\"
        }"]

该结构中将有多个项目。我遇到的问题是编写 for 循环以进入关卡，并搜索周日上午 10 点之前营业的企业。

所以是这样的：

def count_businesses(object):
    for i in object:
        for j in i:
        ....

但是当我达到那个级别时，它似乎会输出字典中的每一个字母。另外，我不确定如何编写函数来查找打开的日期和时间，对我来说必须在上午 10 点之前找到星期日，然后返回计数。时间在这个对象的字典内的数组中，如图所示。

任何帮助将不胜感激！

Answer 1

python 字典是什么似乎有些混淆。 businesses 中的数组中的数据实际上是 JavaScript 对象表示法 (JSON) 中的字符串，python 将其视为字符串。要将其用作 python 字典，您需要使用 python 的 json 库对其进行转换。转换看起来像，

import json

python_obj = json.loads(json_str)

您提供的对象是一个 JSON 字符串数组，例如

businesses = ["{\"hours\":"
            "{"
            "\"tuesday\": [[\"11:30\", \"23:00\"]],"
            "\"thursday\": [[\"11:30\", \"23:00\"]],"
            "\"wednesday\": [[\"11:30\", \"23:00\"]],"
            "\"friday\": [[\"11:30\", \"23:00\"]],"
            "\"sunday\": [[\"9:00\", \"23:00\"]],"
            "\"monday\": [[\"11:30\", \"23:00\"]],"
            "\"saturday\": [[\"11:30\", \"23:00\"]]"
            "},"
            "\"name\": \"XYZ\""
        "}"]

python 字典的数组如下所示

businesses = [
    {
        "hours":{
            "tuesday":[["11:30","23:00"]],
            "thursday":[["11:30","23:00"]],
            "wednesday":[["11:30","23:00"]],
            "friday":[["11:30", "23:00"]],
            "sunday":[["9:00", "23:00"]],
            "monday":[["11:30", "23:00"]],
            "saturday":[["11:30", "23:00"]]
        },
        "name":"XYZ"
    }
]

因此，您看到它输出每个字母的原因是因为您正在遍历字符串，而不是 python 字典。当 python 遍历一个字符串时，它会遍历每个字符。就像下面这样。

string_data = "123456789"
# will iterate through each character
for i in string_data:
    print(i) # will print 9 times each time outputting a character in order

至于函数，您需要确保在进行时间比较时，您使用的是 Python 时间对象而不是字符串，因为这样可以准确地比较时间。我不完全确定为什么时间会列在嵌套数组中，例如[["11:30","23:00"]]，因此如果其他业务的数据格式不同，您可能需要修改以下函数。

这是一个描述你需要什么的函数。

import json, datetime

businesses = ["{\"hours\":"
            "{"
            "\"tuesday\": [[\"11:30\", \"23:00\"]],"
            "\"thursday\": [[\"11:30\", \"23:00\"]],"
            "\"wednesday\": [[\"11:30\", \"23:00\"]],"
            "\"friday\": [[\"11:30\", \"23:00\"]],"
            "\"sunday\": [[\"9:00\", \"23:00\"]],"
            "\"monday\": [[\"11:30\", \"23:00\"]],"
            "\"saturday\": [[\"11:30\", \"23:00\"]]"
            "},"
            "\"name\": \"XYZ\""
        "}"]


def count_businesses(business_list):
    """
    :param business_list: An array of business in JSON to query from
    :return: Int of the count of businesses that are open on Sunday before 10 am
    """

    # initialize the array that will contain the businesses that meet the search criteria
    businesses_found = []

    # python time object of 10:00am that will be used to check against
    opening_business_time = datetime.time(hour=10)

    # iterate through each busineses to check if it meets the search criteria
    for business in business_list:

        # since each business is in JSON, we convert it into a Python object
        business_obj = json.loads(business)

        # Look into the 'hours' key, then the 'sunday' key and get the first item in the array. ( i.e ["11:30","23:00"])
        sunday_hours = business_obj["hours"]["sunday"][0]

        # read in the sunday opening hours as a string from the first value of the array. {i.e "11:30")
        sunday_opening_hours_str = sunday_hours[0]

        # convert the sunday opening hours into a time object so it can be compared.
        # '%H:%M' looks for the format HH:MM in a string.
        # for more reference. https://docs.python.org/3.6/library/datetime.html#strftime-and-strptime-behavior
        sunday_opening_hours_time = datetime.datetime.strptime(sunday_opening_hours_str, '%H:%M').time()

        # if sunday opening hours is before 10 am
        if sunday_opening_hours_time < opening_business_time:

            # add the business object to the list
            businesses_found.append(business_obj)

    # returns the count of the businesses that met the search criteria
    return len(businesses_found)


total = count_businesses(businesses)

print(total)

Answer 2

将此添加为星期日的空检查条件。

if("sunday" in business_obj["hours"])