pandas.api.extensions.register_index_accessor#
- pandas.api.extensions.register_index_accessor(name)[source]#
Register a custom accessor on Index objects.
- Parameters
- namestr
Name under which the accessor should be registered. A warning is issued if this name conflicts with a preexisting attribute.
- Returns
- callable
A class decorator.
See also
register_dataframe_accessor
Register a custom accessor on DataFrame objects.
register_series_accessor
Register a custom accessor on Series objects.
register_index_accessor
Register a custom accessor on Index objects.
Notes
When accessed, your accessor will be initialized with the pandas object the user is interacting with. So the signature must be
def __init__(self, pandas_object): # noqa: E999 ...
For consistency with pandas methods, you should raise an
AttributeError
if the data passed to your accessor has an incorrect dtype.>>> pd.Series(['a', 'b']).dt Traceback (most recent call last): ... AttributeError: Can only use .dt accessor with datetimelike values
Examples
In your library code:
import pandas as pd @pd.api.extensions.register_dataframe_accessor("geo") class GeoAccessor: def __init__(self, pandas_obj): self._obj = pandas_obj @property def center(self): # return the geographic center point of this DataFrame lat = self._obj.latitude lon = self._obj.longitude return (float(lon.mean()), float(lat.mean())) def plot(self): # plot this array's data on a map, e.g., using Cartopy pass
Back in an interactive IPython session:
In [1]: ds = pd.DataFrame({"longitude": np.linspace(0, 10), ...: "latitude": np.linspace(0, 20)}) In [2]: ds.geo.center Out[2]: (5.0, 10.0) In [3]: ds.geo.plot() # plots data on a map