/geopandas

Python tools for geographic data

Primary LanguagePythonBSD 3-Clause "New" or "Revised" LicenseBSD-3-Clause

GeoPandas build status Coverage Status Join the chat at https://gitter.im/geopandas/geopandas Binder DOI

Python tools for geographic data

Introduction

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).

Install

See the installation docs for all details. GeoPandas depends on the following packages:

  • pandas
  • shapely
  • fiona
  • pyproj

Further, descartes and matplotlib are optional dependencies, required for plotting, and rtree is an optional dependency, required for spatial joins. rtree requires the C library libspatialindex.

Those packages depend on several low-level libraries for geospatial analysis, which can be a challenge to install. Therefore, we recommend to install GeoPandas using the conda package manager. See the installation docs for more details.

Get in touch

  • Ask usage questions ("How do I?") on StackOverflow or GIS StackExchange.
  • Report bugs, suggest features or view the source code on GitHub.
  • For a quick question about a bug report or feature request, or Pull Request, head over to the gitter channel.
  • For less well defined questions or ideas, or to announce other projects of interest to GeoPandas users, ... use the mailing list.

Examples

>>> import geopandas
>>> from shapely.geometry import Polygon
>>> 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 = geopandas.GeoSeries([p1, p2, p3])
>>> g
0         POLYGON ((0 0, 1 0, 1 1, 0 0))
1    POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))
2    POLYGON ((2 0, 3 0, 3 1, 2 1, 2 0))
dtype: geometry

Example 1

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)
0    POLYGON ((-0.3535533905932737 0.35355339059327...
1    POLYGON ((-0.5 0, -0.5 1, -0.4975923633360985 ...
2    POLYGON ((1.5 0, 1.5 1, 1.502407636663901 1.04...
dtype: geometry

Example 2

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 = geopandas.read_file(nybb_path)
>>> boros.set_index('BoroCode', inplace=True)
>>> boros.sort_index(inplace=True)
>>> boros
               BoroName     Shape_Leng    Shape_Area  \
BoroCode                                               
1             Manhattan  359299.096471  6.364715e+08   
2                 Bronx  464392.991824  1.186925e+09   
3              Brooklyn  741080.523166  1.937479e+09   
4                Queens  896344.047763  3.045213e+09   
5         Staten Island  330470.010332  1.623820e+09   

                                                   geometry  
BoroCode                                                     
1         MULTIPOLYGON (((981219.0557861328 188655.31579...  
2         MULTIPOLYGON (((1012821.805786133 229228.26458...  
3         MULTIPOLYGON (((1021176.479003906 151374.79699...  
4         MULTIPOLYGON (((1029606.076599121 156073.81420...  
5         MULTIPOLYGON (((970217.0223999023 145643.33221...  

New York City boroughs

>>> boros['geometry'].convex_hull
BoroCode
1    POLYGON ((977855.4451904297 188082.3223876953,...
2    POLYGON ((1017949.977600098 225426.8845825195,...
3    POLYGON ((988872.8212280273 146772.0317993164,...
4    POLYGON ((1000721.531799316 136681.776184082, ...
5    POLYGON ((915517.6877458114 120121.8812543372,...
dtype: geometry

Convex hulls of New York City boroughs