topic Re: Buffering Multiple feature classes in GDB (python) in Python Questions

Buffering Multiple feature classes in GDB (python)

EthanHeidtman — Fri, 08 May 2015 14:55:07 GMT

I am having trouble buffering multiple feature classes within a GDB. These feature classes were just created based on a select by attribute and copy features tool run.

I have attached a copy of my script. The buffer analysis begins at the bottom, I have tried various parameters and dont know the variable that will be my input features that are the selected krogers from each county.

Thanks a lot!

Re: Buffering Multiple feature classes in GDB (python)

DarrenWiens2 — Fri, 08 May 2015 16:54:43 GMT

Are you getting an error or is it just not doing what you want it to do?

Re: Buffering Multiple feature classes in GDB (python)

EthanHeidtman — Fri, 08 May 2015 17:09:17 GMT

It won't even run the buffer analysis.

I think I need to put it in a loop somehow.

Something like list featureclasses with a where clause being a wild card

*krogerselection

Then the loop being for fc in fcs

Buffer analysis

I'm stumped!

Re: Buffering Multiple feature classes in GDB (python)

IanMurray — Sat, 11 Dec 2021 08:42:30 GMT

So are trying to buffer selected features of each features class that you copied to your GDB?

Original Script(for anyone else who wants to chime in)

import arcpy, os
arcpy.env.workspace = "F:/GEO443/FinalPrj"
arcpy.env.overwriteOutput = True
#Variables holding location of each counties LBRS points
brown = "F:/GEO443/FinalPrj/LBRS_data/Brown_cty/BRO_ADDS.shp"
clermont = "F:/GEO443/FinalPrj/LBRS_data/Clermont_cty/CLE_ADDS.shp"
hancock = "F:/GEO443/FinalPrj/LBRS_data/Hancock_cty/HAN_ADDS.shp"
muskingum = "F:/GEO443/FinalPrj/LBRS_data/Muskingum_cty/MUS_ADDS.shp"
richland = "F:/GEO443/FinalPrj/LBRS_data/Richland_cty/RIC_ADDS.shp"
try:
    print "Creating new file geodatabase..."
    #Creating a new GeoDatabase where shapefiles will be moved
    ##CreateFileGDB_management (out_folder_path, out_name, {out_version})
    arcpy.CreateFileGDB_management ("F:/GEO443/FinalPrj","Final.gdb")
    print "New geodatabase has been created in your FinalPrj folder"
    #Move shapefiles to geodatabase using variables created above
    ##FeatureClassToGeodatabase_conversion (Input_Features, Output_Geodatabase)
    arcpy.FeatureClassToGeodatabase_conversion([brown,clermont,hancock,muskingum,richland],"F:/GEO443/FinalPrj/Final.gdb")
    print "Shapefiles have been moved to the geodatabase"
    arcpy.env.workspace = "F:/GEO443/FinalPrj/Final.gdb"
    print "New workspace: " + arcpy.env.workspace
    ##MakeFeatureLayer_management(in_features,out_layer,{where_clause},{workspace},{field_info})
    ##SelectLayerByAttribute_management (in_layer_or_view,{selection_type},{where_clause})
    ##CopyFeatures_management (in_features,out_feature_class,{config_keyword},{spatial_grid_1},{spatial_grid_2},{spatial_grid_3})
    kroger_selection = ('"COMMENT" = \'KROGER\'')
    fcs = arcpy.ListFeatureClasses()
    for fc in fcs:
        print fc
        print ""
        fc_kroger = fc + "kroger"
        fc_lyr = arcpy.MakeFeatureLayer_management (fc,fc_kroger)
        arcpy.SelectLayerByAttribute_management(fc_lyr,"NEW_SELECTION",kroger_selection)
        arcpy.CopyFeatures_management(fc_lyr,fc + "krogerselection")
    print "Features Copied"
    input_features = arcpy.CopyFeatures_management(fc_lyr,fc + "krogerselection")
    ##Buffer_analysis (in_features, out_feature_class, buffer_distance_or_field, {line_side}, {line_end_type}, {dissolve_option}, {dissolve_field})    
    #set input_features variable for buffer anlaysis

    arcpy.Buffer_analysis(input_features, "KrogerBuffer","1 Mile","","","ALL")
    print "buffer created"

except:
    print arcpy.GetMessages()

You have a few problems, first the input for the buffer tool is invalid, it needs to have a layer or fc as an input, you are setting it equal to a geoprocessing operation. If you are trying to buffer each fc selection individually, you need to put the buffer inside you for-loop and make sure its input is either a feature class or feature layer( fc + "krogerselection" perhaps?). Also, unless you get each output buffer a unique name, they will be overwritten each time through the loop since they will all have the same name. If you want to do a single buffer of all fc selected krogers, you will need to have them all in one feature layer or feature class and you could do the buffer outside the loop.

You have made some good headway on this, keep up the good work.

Re: Buffering Multiple feature classes in GDB (python)

EthanHeidtman — Fri, 08 May 2015 17:39:18 GMT

After the script runs before without the buffer analysis it provides me

with the the county address points feature classss in my GDB and 5 new

feature classes that contain only the Kroger points from each. I.e.

BRO_ADDSkrogerselection

CLE_ADDSkrogerselection

Etc.

I then want to create a 1 mile buffer around each Kroger selection feature

class within the GDB...

This is where I am stuck.

Thank you all for the insight I truly appreciate it.

I could complete this task very easily without using Python. But it is for

a final project and the prof will not answer any questions

Re: Buffering Multiple feature classes in GDB (python)

DarrenWiens2 — Fri, 08 May 2015 17:45:46 GMT

The for loop runs once per feature class it encounters. If you want to do something once per feature class, put it inside the loop.

Re: Buffering Multiple feature classes in GDB (python)

IanMurray — Fri, 08 May 2015 17:46:11 GMT

This might be a good opportunity for you to use model builder to set-up your workflow.

Set it up for one fc in model builder, then you can export the model to a python script, then use your list feature classes to loop through and use each fc as input. This way you know your parameters are working for the buffer to start with(or at least can compare to what is going on now).

If not, you are very close, you just need to make sure for each buffer you are using the fc you made as the input for the buffer. Since the new feature classes are already in your workspace, you would just need to use their name as a string as input for the buffer tool. I would put the buffer in the loop and have it put different names depending on the input fc name.

Re: Buffering Multiple feature classes in GDB (python)

EthanHeidtman — Fri, 08 May 2015 18:28:31 GMT

would it be something like this....

##MakeFeatureLayer_management(in_features,out_layer,{where_clause},{workspace},{field_info})

##SelectLayerByAttribute_management (in_layer_or_view,{selection_type},{where_clause})

##CopyFeatures_management (in_features,out_feature_class,{config_keyword},{spatial_grid_1},{spatial_grid_2},{spatial_grid_3})

kroger_selection = ('"COMMENT" = \'KROGER\'')

fcs = arcpy.ListFeatureClasses()

for fc in fcs:

print fc

print ""

fc_kroger = fc + "kroger"

fc_lyr = arcpy.MakeFeatureLayer_management (fc,fc_kroger)

arcpy.SelectLayerByAttribute_management(fc_lyr,"NEW_SELECTION",kroger_selection)

arcpy.CopyFeatures_management(fc_lyr,fc + "krogerselection")

print "Features Copied"

##Buffer_analysis (in_features, out_feature_class, buffer_distance_or_field, {line_side}, {line_end_type}, {dissolve_option}, {dissolve_field})

#set input_features variable for buffer anlaysis

arcpy.env.workspace = "F:/GEO443/FinalPrj/Final.gdb"

fcList = arcpy.ListFeatureClasses("*krogerselection")

for fc in fcList:

print fc

arcpy.Buffer_analysis(fcList, fcList + "Buff", "1 Mile")

Re: Buffering Multiple feature classes in GDB (python)

MatthewRusso — Fri, 08 May 2015 18:28:43 GMT

put your buffer in the loop and clean go through your logic

Re: Buffering Multiple feature classes in GDB (python)

EthanHeidtman — Fri, 08 May 2015 18:30:44 GMT

what do you mean "and clean go through your logic"Matthew Russo

Re: Buffering Multiple feature classes in GDB (python)

DarrenWiens2 — Sat, 11 Dec 2021 08:42:33 GMT

fcList is a list, but fc is a feature class name. Buffer takes a feature class name, not a list.

If you're not sure what type of object something is, do something like:

print type(fcList)
print type(fc)

Re: Buffering Multiple feature classes in GDB (python)

EthanHeidtman — Fri, 08 May 2015 18:37:26 GMT

Re: Buffering Multiple feature classes in GDB (python)

EthanHeidtman — Fri, 08 May 2015 18:37:53 GMT

do you think it should be something like this ^^

Re: Buffering Multiple feature classes in GDB (python)

DarrenWiens2 — Fri, 08 May 2015 18:49:17 GMT

Here's what your for-loop says:

- For each feature class:

- make a feature layer

- make a selection in the feature layer

- copy the feature layer somewhere

- buffer the feature class

Re: Buffering Multiple feature classes in GDB (python)

EthanHeidtman — Fri, 08 May 2015 18:49:55 GMT

when i run it like that, it creates a buffer for the original fcs in the GBD...

not the new kroger selection fcs.

So I think I just need to figure out what the variable is for the newly created BRO_ADDSkrogerselection (etc.) fcs.

Thanks everybody.

Re: Buffering Multiple feature classes in GDB (python)

EthanHeidtman — Fri, 08 May 2015 18:52:23 GMT

here is the output from the script ran above.

its just running the buffer on the wrong fcs.

Re: Buffering Multiple feature classes in GDB (python)

IanMurray — Fri, 08 May 2015 19:13:24 GMT

then all you need to do is make the selection FC the input, not the fc.

Re: Buffering Multiple feature classes in GDB (python)

EthanHeidtman — Fri, 08 May 2015 19:55:56 GMT

do you think I should run another

listFeatureclass_management with the where clause being something like (*krogerselection)

and then for fc in fcList:

arcpy.Buffer_analysis

Re: Buffering Multiple feature classes in GDB (python)

EthanHeidtman — Fri, 08 May 2015 20:17:06 GMT

does anyone know why my script is stopping after print "features copied and not continuing on to the next line of code..... the list feature classes line.

Re: Buffering Multiple feature classes in GDB (python)

IanMurray — Fri, 08 May 2015 20:19:09 GMT

I believe you are overthinking how all this works too much.

fc isn't an object, but is holding a string value, which is the name of the feature class in your gdb. so when the buffer tool see fc, its actually reading the string that it contains and check your workspace for a fc with that name. You need to have it use a string of your selection FC as input, so all you need to do is have the input add the rest of the file name to it.

So you would want

arcpy.Buffer_analysis(fc + "krogerselection" , blahblah other parameters) to get the selection fc(Bro_ADDSkrogerselection for the first time through the loop)

instead of

arcpy.Buffer_analysis(fc, blahblah other parameters) that gets regular fc(Bro_ADDS for the first time through the loop)