Adding one polygon to a plot using matplotlib-basemap

Question

I have the following code:

from mpl_toolkits.basemap import Basemap
map = Basemap(projection='merc', lat_0=50, lon_0=4,
    resolution = 'l', area_thresh = 0.1,
    llcrnrlon=4, llcrnrlat=50,
    urcrnrlon=40, urcrnrlat=60)

map.drawcoastlines(linewidth=0.15)
map.drawcountries(linewidth=0.15)
map.fillcontinents(color='brown',lake_color='white')
map.drawmapboundary(fill_color='white')

And on top of this map I want to display a shapefile that consists of only one polygon. The polygon defines a closed area. I've found different tutorials on how to manually add polygons or plot multiple polygons from a shapefile, but I am not able to do it for my case. The shapefile attribute table is composed of only two fields: 'c' and 'area'.

For now I have arrived to this

import shapefile

s = shapefile.Reader(filepath,'c',drawbounds=False)
shapes = s.shapes()
records = s.records()
for record, shape in zip(records,shapes):
    lons,lats = zip(*shape.points)
    data = np.array(map(lons, lats)).T
x, y =map(lons,lats) 

Answer 1

Had the same issue, but it's so simple that you never thought about doing it with the many tutorials and modules and kind of similar issues on the net:

map.readshapefile('luthuania', 'any_name_you_like', drawbounds=True)

so for your example:

from mpl_toolkits.basemap import Basemap
map = Basemap(projection='merc', lat_0=50, lon_0=4,
    resolution = 'l', area_thresh = 0.1,
    llcrnrlon=4, llcrnrlat=50,
    urcrnrlon=40, urcrnrlat=60)

map.readshapefile('luthuania', 'any_name_you_like', drawbounds=True, linewidth=2, color='b')

map.drawcoastlines(linewidth=0.15)
map.drawcountries(linewidth=0.15)
map.fillcontinents(color='brown',lake_color='white')
map.drawmapboundary(fill_color='white')

Which gives

The module shapefile, by the way is used by Basemap under the hood: see C:\Python33\Lib\site-packages\mpl_toolkits\basemap\shapefile.py