Applying function to pandas dataframe - python-3.x

Question

I have a pandas dataframe called 'tourdata' consisting of 676k rows of data. Two of the columns are latitude and longitude.
Using the reverse_geocode package I want to convert these coordinates to a country data.
When I call :
import reverse_geocode as rg
tourdata['Country'] = rg.search((row[tourdata['latitude']],row[tourdata['longitude']]))
I get the error :
ValueErrorTraceback (most recent call last)
in ()
1 coordinates = (tourdata['latitude'],tourdata['longitude']),
----> 2 tourdata['Country'] = rg.search((row[tourdata['latitude']],row[tourdata['longitude']]))
~/anaconda/envs/py3/lib/python3.6/site-packages/reverse_geocode/init.py
in search(coordinates)
114 """
115 gd = GeocodeData()
--> 116 return gd.query(coordinates)
117
118
~/anaconda/envs/py3/lib/python3.6/site-packages/reverse_geocode/init.py
in query(self, coordinates)
46 except ValueError as e:
47 logging.info('Unable to parse coordinates: {}'.format(coordinates))
---> 48 raise e
49 else:
50 results = [self.locations[index] for index in indices]
~/anaconda/envs/py3/lib/python3.6/site-packages/reverse_geocode/init.py
in query(self, coordinates)
43 """
44 try:
---> 45 distances, indices = self.tree.query(coordinates, k=1)
46 except ValueError as e:
47 logging.info('Unable to parse coordinates: {}'.format(coordinates))
ckdtree.pyx in scipy.spatial.ckdtree.cKDTree.query()
ValueError: x must consist of vectors of length 2 but has shape (2,
676701)
To test that the package is working :
coordinates = (tourdata['latitude'][0],tourdata['longitude'][0]),
results = (rg.search(coordinates))
print(results)
Outputs :
[{'country_code': 'AT', 'city': 'Wartmannstetten', 'country': 'Austria'}]
Any help with this appreciated. Ideally I'd like to access the resulting dictionary and apply only the country code to the Country column.

Answer 1

The search method expects a list of coordinates. To obtain a single data point you can use "get" method.
Try :
tourdata['country'] = tourdata.apply(lambda x: rg.get((x['latitude'], x['longitude'])), axis=1)
It works fine for me :
import pandas as pd
tourdata = pd.DataFrame({'latitude':[0.3, 2, 0.6], 'longitude':[12, 5, 0.8]})
tourdata['country'] = tourdata.apply(lambda x: rg.get((x['latitude'], x['longitude'])), axis=1)
tourdata['country']
Output :
0 {'country': 'Gabon', 'city': 'Booué', 'country...
1 {'country': 'Sao Tome and Principe', 'city': '...
2 {'country': 'Ghana', 'city': 'Mumford', 'count...
Name: country, dtype: object