Following previous Q&As (Appending point values with pyshp? and Appending using PyShp) I am trying to append new data to shapefile using Pyshp. The specifics of my problem is the need to save the file with the same name (without creating a new file).

This simple example based on Pyshp documentation failes on the attempt of the edited file saving:


import shapefile

#create file
w = shapefile.Writer(shapefile.POINT)
w.field("Lon", "N", 20, 10)
w.field("Lat", "N", 20, 10)
w.field("Z", "N", 20, 10)
w.point(0.0, 0.0)
w.record(0.0, 0.0, 0.0)

#append new record
e = shapefile.Editor(shapefile="test")            <-- Existing file is opened for editing
e.point(1.0, 1.0)
e.record(1.0, 1.0, 1.0)
e.save("test")                                    <-- Script falls out

Here is my traceback:

TypeError                                 Traceback (most recent call last)
<ipython-input-29-e3063921c803> in <module>()
----> 1 e.save("out2")

/usr/local/lib/python3.2/dist-packages/pyshp-1.2.0-py3.2.egg/shapefile.py in save(self, target, shp, shx, dbf)
   1026                 target = temp.name
   1027                 generated = True
-> 1028             self.saveShp(target)
   1029             self.shp.close()
   1030             self.saveShx(target)

/usr/local/lib/python3.2/dist-packages/pyshp-1.2.0-py3.2.egg/shapefile.py in saveShp(self, target)
    983             self.shapeType = self._shapes[0].shapeType
    984         self.shp = self.__getFileObj(target)
--> 985         self.__shapefileHeader(self.shp, headerType='shp')
    986         self.__shpRecords()

/usr/local/lib/python3.2/dist-packages/pyshp-1.2.0-py3.2.egg/shapefile.py in __shapefileHeader(self, fileObj, headerType)
    713         z = self.zbox()
    714         # Measure
--> 715         m = self.mbox()
    716         try:
    717             f.write(pack("<4d", z[0], z[1], m[0], m[1]))

/usr/local/lib/python3.2/dist-packages/pyshp-1.2.0-py3.2.egg/shapefile.py in mbox(self)
    685     def mbox(self):
    686         """Returns the current m extremes for the shapefile."""
--> 687         return self.__mbox(self._shapes)
    689     def __shapefileHeader(self, fileObj, headerType='shp'):

/usr/local/lib/python3.2/dist-packages/pyshp-1.2.0-py3.2.egg/shapefile.py in __mbox(self, shapes, shapeTypes)
    671             except IndexError:
    672                 pass
--> 673         return [min(m), max(m)]
    675     def bbox(self):

TypeError: unorderable types: NoneType() < int()

It may be an issue with the Editor class. Try this approach which uses a Reader and Writer object to do the same thing: http://geospatialpython.com/2013/10/editing-shapefile.html

  • I finally checked this. Works just perfect. Thank you for a nice lib! Oct 27 '13 at 15:50

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