UE3

#!/usr/bin/env python

#==============================================================================
#title           :heuberger_buffer.py
#description     :Creates 10 buffers for a given input file ranging from 1000
#                 to 10000 meters in steps of 1000 meters.
#author          :Thomas Heuberger
#date            :2012-12-03
#version         :
#usage           :python heuberger_buffer.py --help
#usage           :heuberger_buffer.py --shapefile c:\temp\Center_0.shp\center_0.shp --outputdirectory c:\temp\test --refresharea
#notes           :
#python_version  :2.7.3
#arcgis_version  :10.1 build 3143
#==============================================================================

import arcpy
import argparse
import os.path
import datetime
import sys

# set up the command line argument parser
parser = argparse.ArgumentParser(description="Creates 10 buffers for a given input file ranging from 1000 to 10000 meters in steps of 1000 meters.")
parser.add_argument('-shp', '--shapefile', help="The input Shapefile. If not specified, Center_0.shp\center_0.shp from the directory where the .py resides is used. You must specify the full qualified path to a valid .shp file, not just a directory name")
parser.add_argument('-ra', '--refresharea', help="Triggers the recalculation of the Shape_Area field so that the correct value is shown in ArcMap. Regardles of this setting the output of the script is always correct", action="store_true")
parser.add_argument('-out', '--outputdirectory', help="Sets the directory used for the buffer files. Uses the current directory if not specified")
# parse the command line arguments
args = parser.parse_args()

# the fully qualified path of the current .py file
workingDir = os.path.abspath(os.path.dirname(__file__))

# If the input shapefile was specified, use it. if not use default 'Center_0.shp\center_0.shp'
shapeFile = args.shapefile if args.shapefile else workingDir + '\\' + 'Center_0.shp\\center_0.shp'

# List of file extensions
ext = ["dbf", "prj", "sbn", "sbx", "shp", "shp.xml", "shx"]

### PREFLIGHT CHECKS

# Check if the input Shapefile exists. Abort if not.
if not os.path.isfile(shapeFile):
    sys.exit("\r\nShapefile \"{}\" not found. \r\n Run {} --help for help. Aborting...".format(shapeFile, os.path.basename(__file__)))

# If an output directory was specified, check if it exists. Abort if not.
if args.outputdirectory and not os.path.exists(args.outputdirectory):
    sys.exit("\r\nSpecified output directory \"{}\" not found. \r\n Aborting...".format(args.outputdirectory))
elif args.outputdirectory:
    outputDir = args.outputdirectory
else:
    outputDir = workingDir + '\\' + 'bufferShapefiles'
    # try to create the ouput directory for the buffer files.
    if not os.path.exists(outputDir):
        try:
            os.makedirs(outputDir)
        except:
            sys.exit("Error creating output directory. Aborting...")

# Set the Workspace
arcpy.env.workspace = outputDir
# overwrite existing files aka delete existing ones. disabled in favor of Python's os.remove(). see below
#arcpy.env.overwriteOutput = True

msg = "\r\nShapefile found, start buffering!"
print msg
print "=" * len(msg)
print "\r\n" * 2

# create a range from 1000 to 10000 with steps of 1000
try:
    for x in xrange(1000, 11000, 1000):
        # The File for the current buffer, ie. buffer_1000.shp
        bufferFile =  outputDir + '\\' + "buffer_{}.shp".format(x)

        # a little housekeeping. check for existing files and remove. do this for every extension.
        # see the ext list above for the list of extensions.
        # I'm specifially not using wildcard matching here to prevent the deletion of the ueber-important buffer_1000.readme!!! file
        for extension in ext:
                thisFile = outputDir + '\\' + "buffer_{}.{}".format(x, extension)
                if os.path.isfile(thisFile):
                    os.remove(thisFile)

        timestamp = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S %f")
        # Create the buffer
        arcpy.Buffer_analysis(shapeFile, bufferFile, "{} Meters".format(x))

        # If the script was invoked with the --refresharea parameter, trigger an update of the Shape_Area field
        if args.refresharea:
            # Update the Shape_Area
            arcpy.CalculateField_management(bufferFile, "Shape_Area", "float('!shape.area@squaremeters!')", "PYTHON")

        # There is just one row in each buffer file, so print will only get called once per Shapefile
        with arcpy.da.SearchCursor(bufferFile, ("SHAPE@AREA")) as cursor:
            for row in cursor:
                print "File {} processed {} - Area: {} m2.".format("buffer_{}".format(x), timestamp, "{0:.2f}".format(row[0]))
except:
    exMessage = ""
    # Iterate through the collecion of traceback messages (if present) and compose the error message shown to the user
    for ex in sys.exc_info():
        try:
            exMessage = exMessage + str(ex.message) + "\r\n"
        except:
            # current traceback has no ex.message attribute. pass
            pass
    sys.exit("\r\nError processing the buffer Shapefiles. \r\n The error was {} \r\n Aborting ...".format(exMessage))