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

Question

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 returns 一个空的 JSON 结果是因为在搜索中没有被查询的地点，它会抛出一个 KeyError 因为代码引用的数据框中的列不' 不存在，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 结果为空白的实例。

我已经尝试 try/except/if 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”。

如有任何建议，我们将不胜感激。

## 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

当 API 结果为空时出错（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]"

Answer 1

如果您只是想让 KeyError 静音，那么试试这个：

try:
   ...
except KeyError as ke:
   pass

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

How to suppress KeyError in Python when dataframe is empty when mapping multiple Foursquare results and an API result is blank

python

pandas

foursquare

keyerror

folium