有没有办法使用 python 中的 API 中的数据循环 function 以获得单独的输入？

Question

我可能用错了标题。 我想知道是否可以为特定输入重复 function。 显示代码会更容易解释。 这是代码：

from urllib.request import urlopen
import json

def askbot(bus_stop):

    if bus_stop == "CU2":
        url = urlopen("https://transportapi.com/v3/uk/bus/stop/43001053801/live.json?app_id=&app_key=&group=route&nextbuses=yes")
        data = json.loads(url.read().decode())
        json_str=json.dumps(data)
        resp=json.loads(json_str)  
        which_line = input("Which bus line would you like to know? ")
        if which_line == "10":
           print("Here is the current expected departure time at bus stop " + bus_stop + " for bus line " + resp['departures']['10'][0]['line_name'] + " heading to " + resp['departures']['10'][0]['direction'])
           print("Expected departure time: " + resp['departures']['10'][0]['expected_departure_time'])
           print("The next bus at bus stop " + bus_stop + "," + " for bus line " + resp['departures']['10'][1]['line_name'] + " will be heading to " + resp['departures']['10'][1]['direction'])
        elif which_line == "8":
            print
        else:
            print("That is not a valid line!")
    else:
        print("That bus stop does not exist!")
which_stop = input("Which bus stop timetable would you like to know? ")

askbot(which_stop)

我的问题是，它在哪里询问用户which_line ，有没有办法让机器人自动搜索输入的公交线路的预期出发时间，而无需手动复制每条公交线路的代码？ 例如，如果我为公交车站“CU2”输入公交线路“8”，机器人将检查该站点的 API 并找到公交线路“8”并打印预计出发时间。

如果需要，我可以提供更多详细信息。

Answer 1

假设索引与您在上面的操作方式相似，可能会沿着这些思路：

which_line = input("Which bus line would you like to know? ")

try:
    print("Here is the current expected departure time at bus stop " + bus_stop + " for bus line " +
        resp['departures'][which_line][0]['line_name'] + " heading to " + resp['departures'][which_line][0]['direction'])
    print("Expected departure time: " +
        resp['departures'][which_line][0]['expected_departure_time'])
    print("The next bus at bus stop " + bus_stop + "," + " for bus line " +
        resp['departures'][which_line][1]['line_name'] + " will be heading to " + resp['departures'][which_line][1]['direction'])
# If Line was not found
except KeyError as err:
    print("%s is not a valid line: %s" % (which_line, err))

这样，您就不必为所有行编写 if 语句，如果您输入的内容不在您的 dict 中，您应该得到一个 KeyError，因为找不到该元素，在这里我们抓住它，output 您的错误与用户提供的输入一起.

而不是打印出 output 我还建议返回您正在寻找的信息，然后在主循环中打印出来。 这样您的 function 就更可重复使用。 此外，当捕获 KeyError 时，请考虑使用raise （返回自定义错误）或return而不是像我在这里所做的那样打印出来。

Answer 2

您可以将行号作为变量插入。

which_line = input("Which bus line would you like to know? ")
print("Here is the current expected departure time at bus stop " + bus_stop + " for bus line " + resp['departures'][which_line][0]['line_name']

请注意

resp['departures']['10'][0]['line_name']

变成

resp['departures'][which_line][0]['line_name']

---

这也取决于您使用的 API。 如果它可以接受行号，则可以在用户输入行号后调用 API 并仅检索该行的数据。

Answer 3

我推断您不只是重用which_line的原因是因为您不想接受所有值。 如果是这种情况，我建议您创建一个可接受值的列表并将其作为您的条件。

existing_lines = [10, 8, 7, 12, 21]
if which_line in existing_lines:
    print("Here is the current expected departure time at bus stop " + bus_stop + " for bus line " + resp['departures'][which_line][0]['line_name']