Exporting WKB (geometry) to .txt using ArcPy?

Question

How can I export WKB (geometry) to text file using arcpy (ArcGIS)?

When I use the examples that I found on the Internet, it doesn't work. Below it's the code I'd wrote:

## Import arcpy module

import sys
import string
import os
import arcpy

## Global variables:

mxd = arcpy.mapping.MapDocument("current")

IN_FC = arcpy.GetParameterAsText(0)
OUT_Addre = arcpy.GetParameterAsText(1)
OUT_Name = arcpy.GetParameterAsText(2)

## Set progressor
lines = arcpy.GetCount_management(IN_FC)
number = int(fc.getOutput(0))

arcpy.SetProgressor("default","Exporting WKB geometry",0,number,1)

## for row in input
with arcpy.da.SearchCursor(IN_FC, ["OID@", "SHAPE@WKB"]) as cursor:
    for row in cursor: 
## First feature
        elem = IN_FC.getFeatures().next()
        geom = elem.geometry()

## Export into wkb format
        wkb = geom.asWkb()

## Import to ogr geometry
        from osgeo import ogr
        geom_ogr = ogr.CreateGeometryFromWkb(wkb)

## Import to Shapely geometry

        from shapely.wkb import loads
        line = loads(wkb)
        ls = wkb.encode('hex')

## output

        output_file = open(OUT_Addre & OUT_Name & ".txt", 'w')
        output_file.write('\n' & ls.encode('utf-8'))
        output_file.close()

Some errors message:

import ogr or wkb = geom.asWkb() "doesn't exist"

Answer 1

Use SHAPE@WKT to get the geometry in text form. WKB is a binary format.

If you specifically need WKB serialized to a string, then you should look at any of the ways in Python to convert type bytearray to string. You could write the object to hexadecimal values:

with arcpy.da.SearchCursor(IN_FC, ["OID@", "SHAPE@WKB"]) as cursor:
    for row in cursor: 
        wkb = row[1]
        output_file.write(wkb.encode('hex') + '\n')  

Then the question becomes why don't you just serialize the geometry with a common GIS format. You mention shapefile and WKB in the comments, so some more specific information about the software that needs this input could help. If shapefile is a valid format, you could just do:

arcpy.CopyFeatures_management (in_FC, 'out.shp')

In your example you have a for row in cursor iterator combined with a .next(). You don't need both. The iterator will advance to the next row for you. If you only needed the first feature then you could use next without the iterator.

Answer 2

My final code was:

# Import arcpy module

import sys
import string
import os
import arcpy
import binascii

# Global variables:

mxd = arcpy.mapping.MapDocument("current")

IN_FC = arcpy.GetParameterAsText(0)

OUT_Addre = arcpy.GetParameterAsText(1)

OUT_Name = arcpy.GetParameterAsText(2)

with arcpy.da.SearchCursor(IN_FC, ["OID@", "SHAPE@WKB"]) as cursor:

# output
    for row in cursor:
        wkb = row[1]
        output_file = open(OUT_Addre + os.sep + OUT_Name + ".txt", 'a')
        output_file.write(binascii.hexlify(wkb) + '\n')
        output_file.close()