映射多个Foursquare结果且API结果为空时，如何在数据帧为空时抑制Python中的KeyError

如何解决映射多个Foursquare结果且API结果为空时，如何在数据帧为空时抑制Python中的KeyError

我正在检索 Foursquare 场地数据并将其绘制在 folium 地图上。我正在同一张地图上绘制多个 API 调用结果。

当 API 由于搜索中没有查询的场所而返回空的 JSON 结果时，它会抛出 KeyError，因为代码引用了数据帧中不存在的列，因为 API 结果为空。

我想继续显示带有其他结果的地图，并让代码忽略或抑制 API 结果为空的实例。

我尝试过 try/except/if 来测试数据框是否为空白，但无法弄清楚如何“忽略空白并跳到下一个 API 结果”。

任何建议将不胜感激。

## Foursquare Query 11 - name origin location
address = 'Convent Station,NJ' ## Try "Madison,NJ" for working location example
geolocator = Nominatim(user_agent="foursquare_agent")
location = geolocator.geocode(address)
latitude = location.latitude
longitude = location.longitude

## name search parameters
search_query = 'Pharmacy'
radius = 1200

## define corresponding URL
url = 'https://api.foursquare.com/v2/venues/search?client_id={}&client_secret={}&ll={},{}&oauth_token={}&v={}&query={}&radius={}&limit={}'.format(CLIENT_ID,CLIENT_SECRET,latitude,longitude,ACCESS_TOKEN,VERSION,search_query,radius,LIMIT)
results = requests.get(url).json()

## Convert to pandas dataframe
# assign relevant part of JSON to venues
venues = results['response']['venues']
venues
# tranform venues into a dataframe
dataframe = json_normalize(venues)

## Filter results to only areas of interest
# keep only columns that include venue name,and anything that is associated with location
filtered_columns = ['name','categories'] + [col for col in dataframe.columns if col.startswith('location.')] + ['id']
dataframe_filtered = dataframe.loc[:,filtered_columns]

# function that extracts the category of the venue
def get_category_type(row):
  try:
        categories_list = row['categories']
  except:
        categories_list = row['venue.categories']
        
  if len(categories_list) == 0:
        return None
  else:
        return categories_list[0]['name']

# filter the category for each row
dataframe_filtered['categories'] = dataframe_filtered.apply(get_category_type,axis=1)

# clean column names by keeping only last term
dataframe_filtered.columns = [column.split('.')[-1] for column in dataframe_filtered.columns]

## Visualize the data
dataframe_filtered.name

    # add the query 11 pharmacies as blue circle markers
for name,lat,lng,label in zip(dataframe_filtered.name,dataframe_filtered.lat,dataframe_filtered.lng,dataframe_filtered.name+" - "+dataframe_filtered.city+","+dataframe_filtered.state):
  folium.CircleMarker(
        [lat,lng],radius=5,color='blue',popup= label,fill = True,fill_color='blue',fill_opacity=0.6
    ).add_to(venues_map)

    ###
    ###
    ###

 
# display map
print('Location loaded,search parameters defined,url generated,results saved & converted to dataframe,map generated!')
venues_map

API结果为空时报错（搜索半径内没有Foursquare结果）

/usr/local/lib/python3.7/dist-packages/ipykernel_launcher.py:21: FutureWarning:

pandas.io.json.json_normalize is deprecated,use pandas.json_normalize instead

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-57-2deac5f680d4> in <module>()
     24 # keep only columns that include venue name,and anything that is associated with location
     25 filtered_columns = ['name','categories'] + [col for col in dataframe.columns if col.startswith('location.')] + ['id']
---> 26 dataframe_filtered = dataframe.loc[:,filtered_columns]
     27 
     28 # function that extracts the category of the venue

6 frames
/usr/local/lib/python3.7/dist-packages/pandas/core/indexing.py in _validate_read_indexer(self,key,indexer,axis,raise_missing)
   1296             if missing == len(indexer):
   1297                 axis_name = self.obj._get_axis_name(axis)
-> 1298                 raise KeyError(f"None of [{key}] are in the [{axis_name}]")
   1299 
   1300             # We (temporarily) allow for some missing keys with .loc,except in

KeyError: "None of [Index(['name','categories','id'],dtype='object')] are in the [columns]"

解决方法

如果您只想让 KeyError 静音，请尝试以下操作：

try:
   ...
except KeyError as ke:
   pass