【发布时间】：2020-02-11 23:35:08
【问题描述】：
我正在开展一个项目，我正在利用 Foursquare API 从波特兰周围的地点提取场地信息。尝试从 json 字典中提取信息并使用我编写的自定义函数将其结构化为数据框时，我遇到了问题。出于某种原因，我编写的函数在字典中的“组”部分标记了一个 KeyError，即使其中有项目并且它存在于字典中。我有一种预感，由于字典中的某些组没有任何项目时，可能会触发 KeyError。
例如：（查看底部的“项目”子组，您会看到有一个空列表。我的函数正在该子组中查找信息，所以这可能是标记错误的原因，）
{'meta': {'code': 200, 'requestId': '5e4330219fcb92001bd8a847'},
'response': {'warning': {'text': 'There aren\'t a lot of results for "(\'Bookstore\', \'Comic Shop\', \'Used Bookstore\', \'Library\')." Try something more general, reset your filters, or expand the search area.'},
'headerLocation': 'University Park',
'headerFullLocation': 'University Park, Portland',
'headerLocationGranularity': 'neighborhood',
'query': 'bookstore comic shop used bookstore library',
'totalResults': 0,
'suggestedBounds': {'ne': {'lat': 45.5830000045, 'lng': -122.72538279609336},
'sw': {'lat': 45.573999995499996, 'lng': -122.73821720390666}},
'groups': [{'type': 'Recommended Places',
'name': 'recommended',
'items': []}]}}
与此相比，来自 API 请求的“正常”字典应该是这样的：
{'meta': {'code': 200, 'requestId': '5e4335769da7ee001b203b56'},
'response': {'warning': {'text': 'There aren\'t a lot of results for "(\'Bookstore\', \'Comic Shop\', \'Used Bookstore\', \'Library\')." Try something more general, reset your filters, or expand the search area.'},
'headerLocation': 'Cathedral Park',
'headerFullLocation': 'Cathedral Park, Portland',
'headerLocationGranularity': 'neighborhood',
'query': 'bookstore comic shop used bookstore library',
'totalResults': 2,
'suggestedBounds': {'ne': {'lat': 45.5928000045, 'lng': -122.7515716757994},
'sw': {'lat': 45.583799995499994, 'lng': -122.76440832420062}},
'groups': [{'type': 'Recommended Places',
'name': 'recommended',
'items': [{'reasons': {'count': 0,
'items': [{'summary': 'This spot is popular',
'type': 'general',
'reasonName': 'globalInteractionReason'}]},
'venue': {'id': '5632a8dc498e5636877e4fa3',
'name': 'Comic Cave PDX',
'location': {'address': '1920 N. Kirkpatrick',
'crossStreet': 'Denver',
'lat': 45.59002437301252,
'lng': -122.75552067488051,
'labeledLatLngs': [{'label': 'display',
'lat': 45.59002437301252,
'lng': -122.75552067488051}],
'distance': 271,
'postalCode': '97217',
'cc': 'US',
'city': 'Portland',
'state': 'OR',
'country': 'United States',
'formattedAddress': ['1920 N. Kirkpatrick (Denver)',
'Portland, OR 97217',
'United States']},
'categories': [{'id': '52f2ab2ebcbc57f1066b8b18',
'name': 'Comic Shop',
'pluralName': 'Comic Shops',
'shortName': 'Comic Shop',
'icon': {'prefix': 'https://ss3.4sqi.net/img/categories_v2/shops/comic_',
'suffix': '.png'},
'primary': True}],
'photos': {'count': 0, 'groups': []}},
'referralId': 'e-0-5632a8dc498e5636877e4fa3-0'},
{'reasons': {'count': 0,
'items': [{'summary': 'This spot is popular',
'type': 'general',
'reasonName': 'globalInteractionReason'}]},
'venue': {'id': '5d617b8e228cfc0008fb1f9f',
'name': 'Two Rivers Bookstore',
'location': {'address': '8836 N Lombard St',
'lat': 45.591434,
'lng': -122.75648600000001,
'labeledLatLngs': [{'label': 'display',
'lat': 45.591434,
'lng': -122.75648600000001}],
'distance': 368,
'postalCode': '97203',
'cc': 'US',
'city': 'Portland',
'state': 'OR',
'country': 'United States',
'formattedAddress': ['8836 N Lombard St',
'Portland, OR 97203',
'United States']},
'categories': [{'id': '4bf58dd8d48988d114951735',
'name': 'Bookstore',
'pluralName': 'Bookstores',
'shortName': 'Bookstore',
'icon': {'prefix': 'https://ss3.4sqi.net/img/categories_v2/shops/bookstore_',
'suffix': '.png'},
'primary': True}],
'photos': {'count': 0, 'groups': []}},
'referralId': 'e-0-5d617b8e228cfc0008fb1f9f-1'}]}]}}
我最近添加了一个 except 子句，它允许函数执行，但是当我使用它时，每个项目都被标记为异常（即使是字典中应该有项目的拉取）。我的代码和错误如下：
我的代码：
def getNearbyVenues(names, latitudes, longitudes, limit=500):
venues_list=[]
for name, lat, lng in zip(names, latitudes, longitudes):
print(name)
url = 'https://api.foursquare.com/v2/venues/explore?&client_id={}&client_secret={}&ll={},{}&v={}&query={}&radius={}&limit={}'.format(
CLIENT_ID,
CLIENT_SECRET,
VERSION,
lat,
lng,
query,
radius,
LIMIT)
try:
results = requests.get(url, "none").json()['response']['groups'][0]['items']
venues_list.extend([(
name,
lat,
lng,
v['venue']['name'],
v['venue']['location']['lat'],
v['venue']['location']['lng'],
v['venue']['categories'][0]['name']) for v in results])
except KeyError:
venues_list.extend([(
name,
lat,
lng,
np.nan,
np.nan,
np.nan,
np.nan)])
nearby_venues = pd.DataFrame(venues_list, columns = ['Neighborhood',
'Neighborhood Latitude',
'Neighborhood Longitude',
'Venue',
'Venue Latitude',
'Venue Longitude',
'Venue Category'])
return(nearby_venues)
（作为旁注，结果中的 0 是什么拉上 (['responses']['groups'][0]['items]) 到底在做什么？从我的课程中借用这部分代码正在努力。
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
<ipython-input-16-66be6cf8c7d3> in <module>
1 PDX_venues = getNearbyVenues(names=PDX_NeighDF['Neighborhood'],
2 latitudes=PDX_NeighDF['Latitude'],
----> 3 longitudes=PDX_NeighDF['Longitude']
4 )
5
<ipython-input-15-dab42c6d540d> in getNearbyVenues(names, latitudes, longitudes, limit)
15
16 #try:
---> 17 results = requests.get(url, "none").json()['response']['groups'][0]['items']
18
19
KeyError: 'groups'
这是试图构建数据框的函数：
PDX_venues = getNearbyVenues(names=PDX_NeighDF['Neighborhood'],
latitudes=PDX_NeighDF['Latitude'],
longitudes=PDX_NeighDF['Longitude']
)
PDX_venues.head()
output: (structured in a pandas df normally)
Neighborhood Neighborhood Latitude Neighborhood Longitude Venue Venue Latitude Venue Longitude Venue Category
0 CATHEDRAL PARK 45.58830 -122.75799 NaN NaN NaN NaN
1 UNIVERSITY PARK 45.57850 -122.73180 NaN NaN NaN NaN
2 PIEDMONT 45.56510 -122.66820 NaN NaN NaN NaN
3 WOODLAWN 45.56970 -122.65240 NaN NaN NaN NaN
4 ARBOR LODGE 45.57354 -122.69240 NaN NaN NaN NaN
非常感谢任何帮助！如果您需要有关代码的更多信息或背景，请告诉我，我很乐意提供更多信息。
【问题讨论】：
-
出于某种原因，我编写的函数在字典的“组”部分标记了一个 KeyError，即使其中有项目并且它存在于字典中。我有一种预感，KeyError 可能是由于字典中的某些组在其中没有任何项目而触发的。 KeyError 不应该是由列表是否为空引起的。您需要拆分
results = requests.get(url, "none").json()['response']['groups'][0]['items']行，并检查每个步骤的结果。
标签： python pandas dataframe dictionary keyerror