Plot shapefile with islands with matplotlib

Question

I am trying to plot a city shapefile with matplotlib's plt.plot()-function. However, within the closed areas I occasionally have small "islands" which lie within the city but not part of it. Therefore I have a solid line connecting one part to "island" as can be seen in the red area:

Any idea how I can prevent this from happening?

Update:

The points for the coloured area looks like this: https://textuploader.com/1kv27 (full shape-data can be downloaded here: https://www.suche-postleitzahl.org/download_files/public/plz-gebiete.shp.zip)

and is plotted with

import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.gca()
x = [i[0] for i in points][:]
y = [i[1] for i in points][:]
ax.plot(x, y, 'k')

I do face the same problem when I want to plot a state which has islands, the islands will be connected to the mainland with a line.

Answer 1

With a polygons shapefile, look at Plot shapefile with matplotlib

You need to use matplotlib paths and patches and there is a Python module dedicated to plot polygons from shapefiles using these functions Descartes.

With your problematic Polygon (directly extracted from the shapefile and not build with your points)

from descartes import PolygonPatch
BLUE = '#6699cc'
GRAY = '#999999'
fig = plt.figure() 
ax = fig.gca() 
ax.add_patch(PolygonPatch(poly, fc=GRAY, ec=BLUE, alpha=0.5, zorder=2 ))
ax.axis('scaled')
plt.show()

Zoom to see the island

You can also directly use GeoPandas (uses Descartes)

import geopandas as gpd
df = gpd.read_file("extract_plz-gebiete.shp")
fig, ax = plt.subplots()
df.plot(ax=ax,color='white', edgecolor='black')
ax.set_aspect('equal')
plt.show()