Shapely & Fiona sample code.

s0.py

import fiona
from shapely.geometry import shape
from shapely.geometry import Polygon
from shapely.geometry import geo

p0 = geo.box(116, 22, 117, 23)
def main():
  shapes = []
  fa = fiona.open('c1/continent.shp')
  n = 0
  ps = 0
  for r in fa:
    n += 1
    g = r['geometry']
    print(g['type'])
    m = 0
    
    for p in g['coordinates']:
      m += 1
      ps += len(p[0])
      if len(p) <= 1:
        continue
      print('%d.%d:%d' % (n, m, len(p[0])))
    
    x = shape(g)
    shapes.append(x)
  fa.close()
  for s in shapes:
    x = s.intersection(p0)
    if (x.is_empty):
      continue
    print(x.exterior)
    print(x.exterior.length)
    v = x.exterior.difference(p0.exterior)
    print(v)
    print(v.length)
    print(v.buffer(0.0005).area)

  print(ps)

if __name__ == '__main__':
  main()