DOC: add example of simple joining two GeoSeries together (append)

I am writing (extremely basic) script using Geopandas and I am stuck a bit due to missing documentation.

I was happy to fing “merging data” at http://geopandas.org/mergingdata.html because I run into TypeError: unsupported operand type(s) for +: 'GeometryArray' and 'GeometryArray' on attempting to merge data split into two such objects.

Sadly, “Merging Data” docs page is not covering simplest possible way of merging data.

For reference my code:

data = gpd.read_file(in_file)

if "waterway" in data:
    rivers = []
    streams = []
    rivers = data[data["waterway"] == "river"]
    rivers.geometry = rivers['geometry'].buffer(0.000250)
    streams = data[data["waterway"] == "stream"]
    streams.geometry = rivers['geometry'].buffer(0.000025)
    (rivers + streams).to_file(out_file, driver = 'GeoJSON')

EDIT: I asked https://gis.stackexchange.com/questions/340463/merge-two-geometryarray-into-one-one-geometryarray-in-geopandas

[martinfleis]

You are looking for simple append. Reproducible example:

world = gpd.read_file(gpd.datasets.get_path('naturalearth_lowres'))
cities = gpd.read_file(gpd.datasets.get_path('naturalearth_cities'))
merged = world.geometry.append(cities.geometry)

Your example:

data = gpd.read_file(in_file)

if "waterway" in data:
    rivers = []
    streams = []
    rivers = data[data["waterway"] == "river"]
    rivers.geometry = rivers['geometry'].buffer(0.000250)
    streams = data[data["waterway"] == "stream"]
    streams.geometry = rivers['geometry'].buffer(0.000025)
    rivers.append(streams).to_file(out_file, driver = 'GeoJSON')

But yeah, we might add it to docs.

[martinfleis]

You can check #524 and #529. But first check what is already included on geopandas.readthedocs.io and in examples folder.