Clipping shapefile with multi-polygon shapefile in geopandas

Question

I have a shapefile (will be called source-file hereafter), which I need to clip by a multi-polygon shapefile so that I can have a clipped shapefile for each polygon. I tried the geopandas, though I am able to clip the source-file by individually clipping the it by selecting the polygons separately from the multi-polygon shapefile, but when I try to loop over the polygons to automate the clipping process I get the following error:

Error: TypeError: 'mask' should be GeoDataFrame, GeoSeries or(Multi)Polygon, got

Code:

import geopandas as gpd

source = ('source-shapefile.shp')
mask = ('mask_shapefile.shp')
sourcefile = gpd.read_file(source)
maskfile = gpd.read_file(mask)
for row in maskfile.iterrows():
    gpd.clip(sourcefile, row)

user_9441404 · Answer

Two points

https://geopandas.org/en/stable/docs/reference/api/geopandas.clip.html mask can be a GeoDataFrame hence no need for looping
https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.iterrows.html yields a tuple of the index value and named tuple of row. Hence your error is the fact your are passing this tuple to clip()

Have constructed an example. It is far simpler to clip using a GeoDataFrame as the mask.

import geopandas as gpd
import pandas as pd

# lets build a mask for use in clip, multipolygons and polygons
maskfile = gpd.read_file(gpd.datasets.get_path("naturalearth_lowres"))
maskfile = maskfile.loc[maskfile["continent"].eq("Europe") & maskfile["name"].ne("Russia")].pipe(
    lambda d: d.assign(gdp_grp=pd.cut(d["gdp_md_est"], bins=4, labels=list("abcd")))
).dissolve("gdp_grp").reset_index()

sourcefile = gpd.read_file(gpd.datasets.get_path("naturalearth_lowres"))

# now clip, no looping needed
gpd.clip(sourcefile, maskfile)

user_5845342 · Answer

Finally, after 5 hours of research, I am now able clip the shapefile by a multi-polygon shapefile and save the clipped polygons separately with their respective names. Following code may be dirty but it works. code:

import geopandas as gpd
import pandas as pd
import os, sys

source = ('source-shapefile.shp')
mask = ('mask_shapefile.shp')
outpath = ('/outpath')

sourcefile = gpd.read_file(source)
maskfile = gpd.read_file(mask)

clipshape = maskfile.explode()

clipshape.set_index('CATCH_NAME', inplace=True) # CATCH_NAME is attribute column name

for index, row in clipshape['geometry'].iteritems():
    clipped = gpd.clip(sourcefile, row)
    clipped.to_file(os.path.join(outpath, f'{index}.shp'))

Clipping shapefile with multi-polygon shapefile in geopandas

2 Answers