Adding columns to GeoDataFrame

Question

I would like to add columns xmin, xmax, ymin, ymax and I take coordinates from column 'geometry'. I have exemplary dataframe with 1 records. Where is the problem?

Data:

   FID_1        GODLO                                           geometry
0      0  7.101.01.21  POLYGON ((7340000.000 5425000.000, 7340000.000...

I use, but I am getting the error:

TypeError: 'Polygon' object does not support item assignment

import geopandas as gpd

budynki = gpd.read_file('/home/gis/siatki_skorowidzowe/s7_2000/2000s7_2000.shp', rows = slice(0,1), encoding ='cp1250')

xlist = []
ylist = []
for polygon in budynki['geometry']:
    for x, y in polygon.exterior.coords:
        xlist.append(x)
        ylist.append(y)
        for x in xlist:
            minx = float(min(xlist))
            maxx = float(max(xlist))
        for y in ylist:
            miny = float(min(ylist))
            maxy = float(max(ylist))
    polygon['xmin'] = minx
    polygon['xmax'] = maxx
    polygon['ymin'] = miny
    polygon['ymax'] = maxy

Answer 1

polygon is a shapely geometry in your script, not a row. So you cannot add a key as in a dictionary or a column as in (geo)pandas (Geo)DataFrame.

Use this script.

# other lines

def get_bounds(r):
    minx, miny, maxx, maxy =  r["geometry"].bounds    
    r["minx"] = minx
    r["miny"] = miny
    r["maxx"] = maxx
    r["maxy"] = maxy
    return r
    
budynki = budynki.apply(get_bounds, axis=1)