Python tools for geographic data
GeoPandas is a project to add support for geographic data to
pandas objects. It currently implements
GeoSeries
and GeoDataFrame
types which are subclasses of
pandas.Series
and pandas.DataFrame
respectively. GeoPandas
objects can act on shapely
geometry objects and perform geometric operations.
GeoPandas geometry operations are cartesian. The coordinate reference
system (crs) can be stored as an attribute on an object, and is
automatically set when loading from a file. Objects may be
transformed to new coordinate systems with the to_crs()
method.
There is currently no enforcement of like coordinates for operations,
but that may change in the future.
Documentation is available at geopandas.org (current release) and Read the Docs (release and development versions).
Requirements
For the installation of GeoPandas, the following packages are required:
pandas
shapely
fiona
descartes
pyproj
Further, rtree
is an optional
dependency. rtree
requires the C library libspatialindex
. If using brew, you can install using brew install Spatialindex
.
Install
GeoPandas depends on several low-level libraries for geospatial analysis. Depending on the system and package manager that you use, this may cause dependency conflicts if you are not careful.
Using conda
We suggest that you use the anaconda distribution
to install GeoPandas (miniconda
is fine as well).
Use conda
and the conda-forge
channel to install GeoPandas on a clean environment:
conda create -n geopandas
source activate geopandas # 'activate geopandas' on Windows
conda install -c conda-forge geopandas
NOTE: Creating a new environment is not strictly necessary, but installing other geospatial packages
from a different channel than conda-forge
may cause dependency conflicts, so we recommend starting
fresh if possible. See the conda-forge gotcha page
for more information.
Using pip
GeoPandas is also pip-installable. If you choose to use pip
, make sure that you have the proper non-python
libraries installed and linked properly.
pip install geopandas
>>> p1 = Polygon([(0, 0), (1, 0), (1, 1)])
>>> p2 = Polygon([(0, 0), (1, 0), (1, 1), (0, 1)])
>>> p3 = Polygon([(2, 0), (3, 0), (3, 1), (2, 1)])
>>> g = GeoSeries([p1, p2, p3])
>>> g
0 POLYGON ((0.0000000000000000 0.000000000000000...
1 POLYGON ((0.0000000000000000 0.000000000000000...
2 POLYGON ((2.0000000000000000 0.000000000000000...
dtype: object
Some geographic operations return normal pandas object. The area
property of a GeoSeries
will return a pandas.Series
containing the area of each item in the GeoSeries
:
>>> print g.area
0 0.5
1 1.0
2 1.0
dtype: float64
Other operations return GeoPandas objects:
>>> g.buffer(0.5)
Out[15]:
0 POLYGON ((-0.3535533905932737 0.35355339059327...
1 POLYGON ((-0.5000000000000000 0.00000000000000...
2 POLYGON ((1.5000000000000000 0.000000000000000...
dtype: object
GeoPandas objects also know how to plot themselves. GeoPandas uses descartes to generate a matplotlib plot. To generate a plot of our GeoSeries, use:
>>> g.plot()
GeoPandas also implements alternate constructors that can read any data format recognized by fiona. To read a zip file containing an ESRI shapefile with the boroughs boundaries of New York City (GeoPandas includes this as an example dataset):
>>> nybb_path = geopandas.datasets.get_path('nybb')
>>> boros = GeoDataFrame.from_file(nybb_path)
>>> boros.set_index('BoroCode', inplace=True)
>>> boros.sort()
>>> boros
BoroName Shape_Area Shape_Leng \
BoroCode
1 Manhattan 6.364422e+08 358532.956418
2 Bronx 1.186804e+09 464517.890553
3 Brooklyn 1.959432e+09 726568.946340
4 Queens 3.049947e+09 861038.479299
5 Staten Island 1.623853e+09 330385.036974
geometry
BoroCode
1 (POLYGON ((981219.0557861328125000 188655.3157...
2 (POLYGON ((1012821.8057861328125000 229228.264...
3 (POLYGON ((1021176.4790039062500000 151374.796...
4 (POLYGON ((1029606.0765991210937500 156073.814...
5 (POLYGON ((970217.0223999023437500 145643.3322...
>>> boros['geometry'].convex_hull
0 POLYGON ((915517.6877458114176989 120121.88125...
1 POLYGON ((1000721.5317993164062500 136681.7761...
2 POLYGON ((988872.8212280273437500 146772.03179...
3 POLYGON ((977855.4451904296875000 188082.32238...
4 POLYGON ((1017949.9776000976562500 225426.8845...
dtype: object