topic Re: Help GIS Tutorial for Python Scripting ex 2.3 in Python Questions

Help GIS Tutorial for Python Scripting ex 2.3

ChantellKrider — Wed, 14 Jan 2015 17:58:42 GMT

I recently purchased David Allen's GIS tutorial and I'm stuck on exercise 2.3. The objective is to buffer multiple paths with variable buffer distances based on the length of the path -step 7 (I'm stuck here). The exercise uses a search cursor to go through each path and buffer accordingly. The data are available with the book here. I know the buffer line is incorrect, it needs to call fcName and wellBuffDist.

It would be helpful to see the full script...if anyone has already completed this exercise. Thanks.

try:

import arcpy

from arcpy import env

env.workspace = r"C:\EsriPress\GISTPython\Data\City of Oleander.gdb\Well_Data"

env.overwriteOutput = True

fcName = "BC_South_3H_Path"

wellCursor = arcpy.da.SearchCursor(fcName,["Shape_Length"])

for row in wellCursor:

drillLength = row[0]

def wellBuffDist(drillLenght, wellBuffDist):

if drillLenght < 3000:

wellBuffDist = 75

elif drillLenght >= 3000 and drillLenght < 4000:

wellBuffDist = 175

else:

wellBuffDist = 300

# Replace a layer/table view name with a path to a dataset (which can be a layer file) or create the layer/table view within the script

# The following inputs are layers or table views: "BC_South_3H_Path"

arcpy.Buffer_analysis(in_features="BC_South_3H_Path",out_feature_class="C:/EsriPress/GISTPython/MyExercises/Scratch/Temporary Storage.gdb/SelectionBuffer",buffer_distance_or_field="300 feet",line_side="FULL",line_end_type="ROUND",dissolve_option="NONE",dissolve_field="#")

print "great job!"

except:

print "do over"

Re: Help GIS Tutorial for Python Scripting ex 2.3

DallasShearer — Thu, 15 Jan 2015 18:01:05 GMT

this should work...

try:

import arcpy

from arcpy import env

env.workspace = r"C:\EsriPress\GISTPython\Data\City of Oleander.gdb\Well_Data"

env.overwriteOutput = True

fcName = "BC_South_3H_Path"

def wellBuffDist(drillLenght):

if drillLenght < 3000:

BuffDist = 75

elif drillLenght >= 3000 and drillLenght < 4000:

BuffDist = 175

else:

BuffDist = 300

return str(BuffDist) + " feet"

wellCursor = arcpy.da.SearchCursor(fcName,["Shape_Length"])

for row in wellCursor:

drillLength = row[0]

wBuffDist = wellBuffDist(row[0])

arcpy.Buffer_analysis(in_features=fcName, out_feature_class="C:/EsriPress/GISTPython/MyExercises/Scratch/Temporary Storage.gdb/SelectionBuffer", buffer_distance_or_field=wBuffDist, line_side="FULL", line_end_type="ROUND", dissolve_option="NONE", dissolve_field="#")

print "great job!"

except:

print "do over"

Re: Help GIS Tutorial for Python Scripting ex 2.3

ChantellKrider — Thu, 15 Jan 2015 21:18:36 GMT

Dallas-

Wow! thank you sooo much. I really appreciate your response. I did run the code you suggested and it almost works. I commented bits out until I discovered the source of the error. It gets hung up in the buffer statement where it calls the wBuffDist. I'll do a little more work to try and figure it out.

Thanks again!

Re: Help GIS Tutorial for Python Scripting ex 2.3

XanderBakker — Thu, 15 Jan 2015 23:47:14 GMT

Hi Chantell Krider‌,

When you post code, could you please use the syntax highlighting?

Posting Code blocks in the new GeoNet

In case Dallas answer was helpful you can mark it as Helpfull (below the post you'll find "Helpful Yes | No").

In case Dallas answered your question you can mark his post using the button "Correct Answer".

Kind regards, Xander

Re: Help GIS Tutorial for Python Scripting ex 2.3

ChantellKrider — Thu, 15 Jan 2015 23:49:57 GMT

Okay. Thanks. I'm new to this. Thanks for the tip.