2

I am not able to transfer a pandas dataframe column with geolocation coordinates into a Geopandas Point format.

location = pd.read_csv('City_addresses')
print location['Geolocation'].head()

Outputs the following:

0    (50.673675, -120.298973)
1    (50.678354, -120.329258)
2    (50.672496, -120.333317)
3    (50.673359, -120.332912)
4    (50.673411, -120.32978)
Name: Geolocation, dtype: object

Then I attempt to transfer it to Geopandas Point coordinates.

from shapely.geometry import Point
from geopandas import GeoDataFrame

location['Geolocation'] = location['Geolocation'].apply(Point)
gpd = gpd.GeoDataFrame(location, geometry='Geolocation', crs={'init': 'epsg:4326'})

print gpd

To which I get:

TypeError: a float is required

But it won't allow me to change the datatype to a float in pandas either. What should I do?

4

Your coordinates are string representations of tuples, for example "(50.673675, -120.298973)" but:

The Point constructor takes positional coordinate values or point tuple parameters.

So you need to convert the string to 50.673675 and -120.298973 or (50.673675, -120.298973). You can use eval:

location['geometry'] = location.Geolocation.apply(lambda x: Point(eval(x))
1

Your coordinates are stored inside tuples. However, to construct a GeoPandas Object, you need a column usually named "geometry" which store shapely.geometry objects. In your case, the object needs to be Point objects. Therefore, the code to construct a GeoPandasDataFrame would look like:

from shapely.geometry import Point

location = pd.read_csv('City_addresses')
location["geometry"] = location.apply(lambda x: Point(x["Geolocation"][0], x["Geolocation"][1]) , axis = 1)
gdf = gpd.GeoDataFrame(location, geometry='geometry', crs={'init': 'epsg:4326'})
  • You can also do: location['geometry'] = location.Geolocation.apply(lambda x: Point(eval(x))) – BERA Jul 17 '18 at 8:07
  • @yimcai Your solution is giving me a type error, says that the float type is required – user4718221 Aug 5 '18 at 5:32
  • @BERA good to know. – yimcai Aug 5 '18 at 9:20
  • @user4718221 sorry I did not notice that (50.673675, -120.298973) is actually stored as String type "(50.673675, -120.298973)". My method requires some extra string parsing work. Instead, BERA provides a shortcut to save work to parse "(50.673675, -120.298973)" – yimcai Aug 5 '18 at 10:00
  • @yimcai How would you go about swapping the coordinates places? Apparently it needs to be (-120.298973, 50.673675), and I wrote the script below for that. For some reason, its not working. Any ideas? for u in gdf['Geolocation']: u = u.replace('(', '') u = u.replace(')', '') a, b = u.split(',') correct = [b, a] correct = gdf['Geolocation_correct'] – user4718221 Aug 6 '18 at 5:56

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