从None JSONDecodeError引发JSONDecodeError（“期望值”，s，err.value）：期望值

Question

Python3.6

我正试图使用python从Google地图抓取一个区域内公交车站的位置。我读过类似的问题，但仍然没有找到解决办法。

File "d:\ProgramData\Anaconda3\lib\json\decoder.py", line 357, in raw_decode raise JSONDecodeError("Expecting value", s, err.value) from None

JSONDecodeError: Expecting valueHere is the code

回溯：

Traceback (most recent call last):

File "", line 1, in runfile('D:/Dropbox/Lisa/CRC/BusStop/google_place.py', >wdir='D:/Dropbox/Lisa/CRC/BusStop')

File "D:/ProgramData/Anaconda3/lib/site->packages/spyder/utils/site/sitecustomize.py", line 710, in runfile execfile(filename, namespace)

File "D:/ProgramData/Anaconda3/lib/site->packages/spyder/utils/site/sitecustomize.py", line 101, in execfile exec(compile(f.read(), filename, 'exec'), namespace)

File "D:/Dropbox/Lisa/CRC/BusStop/google_place.py", line 123, in main()

File "D:/Dropbox/Lisa/CRC/BusStop/google_place.py", line 117, in main for st, st_lat, st_lng, buses in nearby_bus_stations(lat, lng, apikeys):

File "D:/Dropbox/Lisa/CRC/BusStop/google_place.py", line 73, in >nearby_bus_stations "&rankby=distance&language=zh-TW&type=bus_station")

File "D:/Dropbox/Lisa/CRC/BusStop/google_place.py", line 48, in get_web_json return json.loads(dataform.decode("utf8"))

File "d:\ProgramData\Anaconda3\lib\json__init__.py", line 354, in loads return _default_decoder.decode(s)

File "d:\ProgramData\Anaconda3\lib\json\decoder.py", line 339, in decode obj, end = self.raw_decode(s, idx=_w(s, 0).end())

File "d:\ProgramData\Anaconda3\lib\json\decoder.py", line 357, in raw_decode raise JSONDecodeError("Expecting value", s, err.value) from None

JSONDecodeError: Expecting value

下面是完整的代码：

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import sys
import json
from urllib.request import urlopen, Request
from lxml import html
import random




def warning(msg):
    sys.stderr.write("Warning: %s\n" % msg)


def dump_list(ls):
    return '[' + ','.join(ls) + ']'


def get_webpage(url):
    """ Given a HTTP/HTTPS url and then returns string
    Returns:
        string of HTML source code
    """
    req = Request(url, headers={'Accept-Charset': 'utf-8', 'Accept-Language': 'zh-tw,en-us;q=0.5'})
    with urlopen(req) as rsq:
        _, _, charset = rsq.headers['Content-Type'].partition('charset=')
        if not charset:
            charset = 'utf-8'
        htmlbytes = rsq.readall()
    charset = charset.strip()
    try:
        return str(htmlbytes, charset)
    except (UnicodeDecodeError):
        warning('encoding htmlbytes to {} failed'.format(charset))
        with open('UnicodeDecodeError.html', 'wb') as fout:
            fout.write(htmlbytes)
        raise


def get_web_json(url):
    with urlopen(url) as rsq:
#        return json.loads(str(rsq.readall(), 'utf8'))
        print(str(rsq.read()))
        dataform = rsq.read()
#        print(dataform)
#        return json.loads(str(rsq.read(), 'utf8'))
        return json.loads(dataform.decode("utf8"))
        print(dataform.decode("utf8"))


def random_key(apikeys):
    return apikeys[random.randrange(0, len(apikeys))]


def nearby_bus_stations(lat, lng, apikeys):
    """ Return a list of nearby bus stations around the location
    Args:
        lat: (float) latitude in degrees
        lng: (float) longitude in degrees
        apikey: Google API Key which enables Place API
    Yields:
        tuple(station:str, latitude: float, longitude: float, list[bus: string])
    Example:
        >>> sts = list(nearby_bus_stations(25.021072,121.551788))
        >>> print sts[0]
        ("黎明社教中心", 25.019798, 121.551818, ["懷恩專車S32"])
    """
    for apikey in apikeys:
        places = get_web_json(
            "https://maps.googleapis.com/maps/api/place/nearbysearch/json?" +
            "key=%s&location=%f,%f" % (apikey, lat, lng) +
            "&rankby=distance&language=zh-TW&type=bus_station")
        print("places:",places)#wh
        if places['status'] == 'OK':
            break

    if places['status'] != 'OK':
        warning("status=" + places['status'])
        return

    for result in places['results']:
        placeid = result['place_id']
        for apikey in apikeys:
            detail = get_web_json(
                "https://maps.googleapis.com/maps/api/place/details/" +
                "json?key=%s&placeid=%s" % (apikey, placeid) +
                "&language=zh-TW")
            if detail['status'] == 'OK':
                break
        if detail['status'] != 'OK':
            warning("status=" + detail['status'])
            break
        station = detail['result']['name']
        loc = detail['result']['geometry']['location']

        buspage = get_webpage(detail['result']['url'])
        tree = html.fromstring(buspage)
        bus_elm = tree.xpath("/html/body/div[1]/div/div[4]/div[4]/div/div/div[2]/div/div[2]/div[1]/div[2]/div/div/div[2]/div/table/tr/td")
        if not bus_elm:
            warning('xpath get bus failed')
            continue
        bus_elm = bus_elm[0]
        buses = list(filter(lambda s: len(s.strip()) > 0,
                            bus_elm.text_content().strip().split()))
        yield (station, float(loc['lat']), float(loc['lng']), buses)


def main():
    random.seed()
#    lat, lng = map(float, sys.argv[1].split(','))
    lat, lng = -32.057421,115.770269
#    with open('apikeys.json', mode='r') as f:
#        apikeys = json.load(f)

    apikeys = ["AIzaSyDHRsWPqOZ-LuzAtwCfi2ArKtHH440Pkrk"]
    for st, st_lat, st_lng, buses in nearby_bus_stations(lat, lng, apikeys):
        print('Station: "{}", ({},{}), Buses={}'.format(
            st, st_lat, st_lng, dump_list(buses)))


if __name__ == "__main__":
    main()

Answer 1

函数get_web_json（）应修改为：

def get_web_json(url):
    with urlopen(url) as rsq:
        dataform = rsq.read().decode().replace('\n','')  
        return json.loads(dataform)