问底图readshapefile错误int()的无效文本

EN

shp = fiona.open('Wien_test2.shp')
bds = shp.bounds
shp.close()
extra = 0.01
ll = (float(bds[0]), float(bds[1]))
ur = (float(bds[2]), float(bds[3]))
coords = list(chain(ll, ur))
w, h = coords[2] - coords[0], coords[3] - coords[1]
m = Basemap(
    projection='tmerc',
    lon_0=16.,
    lat_0=48.,
    ellps = 'WGS84',
    llcrnrlon=coords[0] - extra * w,
    llcrnrlat=coords[1] - extra + 0.01 * h,
    urcrnrlon=coords[2] + extra * w,
    urcrnrlat=coords[3] + extra + 0.01 * h,
    lat_ts=0,
    resolution='i',
    suppress_ticks=True)
m.readshapefile(
    'Wien_test2',
    'Wien_test2',
    color='none',
    zorder=2)

Traceback (most recent call last):
  File "maps.py", line 104, in <module>
    zorder=2)
  File "/usr/lib/python2.7/dist-packages/mpl_toolkits/basemap/__init__.py", line 2146, in readshapefile
    for shprec in shf.shapeRecords():
  File "/usr/lib/python2.7/dist-packages/mpl_toolkits/basemap/shapefile.py", line 543, in shapeRecords
    for rec in zip(self.shapes(), self.records())]
  File "/usr/lib/python2.7/dist-packages/mpl_toolkits/basemap/shapefile.py", line 515, in records
    r = self.__record()
  File "/usr/lib/python2.7/dist-packages/mpl_toolkits/basemap/shapefile.py", line 480, in __record
    value = int(value)
ValueError: invalid literal for int() with base 10: '***********'