In [ ]:

    

%matplotlib inline
import os

from IPython.core.display import Image
import numpy as np
import matplotlib.pyplot as plt

import fiona
import mapnik
import shapely.geometry


## Fiona, mapnik demo
##  Live 8.5  *  darkblue-b
##
##   based on UoLPythonGroup/data-hack-0


    

In [ ]:

    

BASE_FOLDER = '/home/user/data/north_carolina/shape'


    

In [ ]:

    

c_shapefile = os.path.join(BASE_FOLDER, 'nc_state.shp')
f = fiona.open(c_shapefile)
shps = list(f)
print 'f: ',type(f)
print f.schema


    

In [ ]:

    

type(f[2])


    

In [ ]:

    

## Use the Shapely geometry classes
##  instantiate a Polygon from the Fiona collection


    

In [ ]:

    

import shapely.geometry

geo = shapely.geometry.shape(f[0]['geometry'])
geo


    

In [ ]:

    

## plt.plot(*geo.xy)  ## hmm not implemented


    

In [ ]:

    

## Mapnik
##  load the Mapnik python interfaces
##  read the shapefile directly with Mapnik libs
##  use the IPython Image interface as the drawing target


    

In [ ]:

    

def show_mapnik(m):
    """Returns an IPython Image of the rendered map."""
    im = mapnik.Image(m.width, m.height)
    mapnik.render(m, im)
    return Image(data=im.tostring('png32'))


    

In [ ]:

    

import mapnik

m = mapnik.Map(600, 600)

layer = mapnik.Layer('contour')
layer.datasource = mapnik.Shapefile(file=c_shapefile)

style = mapnik.Style()
rule = mapnik.Rule()

line_symbolizer = mapnik.LineSymbolizer(mapnik.Color('green'),0.4)
rule.symbols.append(line_symbolizer)

m.layers.append(layer)
style.rules.append(rule)
m.append_style('My Style', style)
layer.styles.append('My Style')

m.layers.append(layer)
m.zoom_all()
show_mapnik(m)


    

In [ ]: