GeoPandas的过度功能无法正常工作

Question

我只是想使用geopandas两个多边形区域的并集和交集。我定义：

import geopandas as gpd
from shapely.geometry import Polygon
polys1 = gpd.GeoSeries([Polygon([(0,0), (2,0), (2,2), (0,2)]),
                                  Polygon([(2,2), (4,2), (4,4), (2,4)])])
polys2 = gpd.GeoSeries([Polygon([(1,1), (3,1), (3,3), (1,3)]),
                                  Polygon([(3,3), (5,3), (5,5), (3,5)])])

df1 = gpd.GeoDataFrame({'geometry': polys1, 'df1':[1,2]})
df2 = gpd.GeoDataFrame({'geometry': polys2, 'df2':[1,2]})

我尝试以下方法来获得union：

res_union = gpd.overlay(df1, df2, how='union')

并且失败并显示以下错误：

AttributeError: 'NoneType' object has no attribute 'intersection'

我正在按照这里的说明进行操作。

Answer 1

尽管我不了解OP的操作系统，但我认为我至少在GNU / Linux系统上已经找到了解决问题的方法（我无法在其他系统上进行测试）。

直接说明

为了能够使用该overlay功能，您不仅需要安装geopandas，还需要安装rtree，但这rtree是C库libspatialindex的包装。因此，要使用rtree库，您需要安装libspatialindexC库。

要安装，请libspatialindex打开终端类型：

sudo apt-get update && apt-get install -y libspatialindex-dev

注意：实际上，您只需要使用sudo apt-get install libspatialindex-dev，但是更新系统是个好习惯，并且-y标志只是为了不停止安装过程而要求是否继续安装。

现在应该可以解决您的问题了。注意：确保已rtree安装在系统中，可以使用pip3 freeze（我假设您使用python3）进行此操作。

详细说明

我遇到了同样的错误，并花了很多时间来找出问题所在。这个问题的答案libspatialindex和python上的Rtree给了我一些如何解决问题的技巧。

考虑以下代码（OP的代码示例），并将其保存为script.py：

import geopandas as gpd
from shapely.geometry import Polygon


polys1 = gpd.GeoSeries([Polygon([(0,0), (2,0), (2,2), (0,2)]),
                        Polygon([(2,2), (4,2), (4,4), (2,4)])])

polys2 = gpd.GeoSeries([Polygon([(1,1), (3,1), (3,3), (1,3)]),
                        Polygon([(3,3), (5,3), (5,5), (3,5)])])

df1 = gpd.GeoDataFrame({'geometry': polys1, 'df1':[1,2]})

df2 = gpd.GeoDataFrame({'geometry': polys2, 'df2':[1,2]})

res_union = gpd.overlay(df1, df2, how='union')

考虑以下几点requirements.txt：

Shapely==1.6.4.post2
descartes==1.1.0
geopandas==0.4.0
matplotlib==3.0.2

如果您尝试仅在requirements.txt和中scrip.py安装rtree库并运行，而不根据来安装库requirements.txt，则会显示以下错误消息：

/usr/local/lib/python3.6/site-packages/geopandas/base.py:76: UserWarning: Cannot generate spatial index: Missing package `rtree`.
  warn("Cannot generate spatial index: Missing package `rtree`.")
Traceback (most recent call last):
  File "script.py", line 17, in <module>
    res_union = gpd.overlay(df1, df2, how='union')
  File "/usr/local/lib/python3.6/site-packages/geopandas/tools/overlay.py", line 371, in overlay
    result = _overlay_union(df1, df2)
  File "/usr/local/lib/python3.6/site-packages/geopandas/tools/overlay.py", line 298, in _overlay_union
    dfinter = _overlay_intersection(df1, df2)
  File "/usr/local/lib/python3.6/site-packages/geopandas/tools/overlay.py", line 212, in _overlay_intersection
    sidx = bbox.apply(lambda x: list(spatial_index.intersection(x)))
  File "/usr/local/lib/python3.6/site-packages/pandas/core/series.py", line 3194, in apply
    mapped = lib.map_infer(values, f, convert=convert_dtype)
  File "pandas/_libs/src/inference.pyx", line 1472, in pandas._libs.lib.map_infer
  File "/usr/local/lib/python3.6/site-packages/geopandas/tools/overlay.py", line 212, in <lambda>
    sidx = bbox.apply(lambda x: list(spatial_index.intersection(x)))
AttributeError: 'NoneType' object has no attribute 'intersection'

错误消息的最后一行

AttributeError: 'NoneType' object has no attribute 'intersection'

不是那么有用。但是，如果您看第一行：

/usr/local/lib/python3.6/site-packages/geopandas/base.py:76: UserWarning: Cannot generate spatial index: Missing package树.

它在抱怨rtree图书馆。

因此，让我们安装rtree并查看会发生什么。requirements.txt现在更新为：

Shapely==1.6.4.post2
descartes==1.1.0
geopandas==0.4.0
matplotlib==3.0.2
rtree==0.8.3

再次运行，script.py我得到以下错误：

Traceback (most recent call last):
  File "script.py", line 3, in <module>
    import geopandas as gpd
  File "/usr/local/lib/python3.6/site-packages/geopandas/__init__.py", line 1, in <module>
    from geopandas.geoseries import GeoSeries
  File "/usr/local/lib/python3.6/site-packages/geopandas/geoseries.py", line 12, in <module>
    from geopandas.base import GeoPandasBase, _series_unary_op, _CoordinateIndexer
  File "/usr/local/lib/python3.6/site-packages/geopandas/base.py", line 14, in <module>
    from rtree.core import RTreeError
  File "/usr/local/lib/python3.6/site-packages/rtree/__init__.py", line 1, in <module>
    from .index import Rtree
  File "/usr/local/lib/python3.6/site-packages/rtree/index.py", line 5, in <module>
    from . import core
  File "/usr/local/lib/python3.6/site-packages/rtree/core.py", line 125, in <module>
    raise OSError("Could not find libspatialindex_c library file")
OSError: Could not find libspatialindex_c library file

最后一行抱怨libspatialindex_c，所以我的回答，“直接的解释”的第一部分所解释的，只需运行娄代码安装libspatialindex和script.py应该工作。

sudo apt-get update && apt-get install -y libspatialindex-dev

至少对我来说问题已经解决了。