NameError: variable not defined even though set multiple times

Question

This code original worked when run through the python command window in ArcCatalog. After I added the script to a toolbox I have had all sorts of troubles.

The most frustrating error has been:

NameError: name 'projectGDB' is not defined

Here is a section of the code. Unfortunately, the error persists. Again, the error only occurs when run as a tool from a toolbox. The NameError does not occur when copied and pasted into the command window.

# Import arcpy module & other helpful 
import arcpy, os, xlwt

# Name Project
projectName = arcpy.GetParameterAsText(0)
if projectName == "#" or not projectName:
    projectName = "TEST"

# Create Project Folder
projPath = arcpy.GetParameterAsText(1)
if projPath == "#" or not projPath:
    projPath = "F:\\GIS\\TEST"
arcpy.AddMessage("Folder path for project is " + projPath)
print "Folder path for project is " + projPath

# Create Project Geodatabase
try: 
    arcpy.CreateFileGDB_management(path, projectName, "CURRENT")
except Exception as e:
    print('Error creating gdb {0} at {1}'.format(projectName, projPath))
    print('Exception: {0}'.format(e.message))

# Set Work Environment
projectGDB = os.path.join(path, projectName + ".gdb")
arcpy.env.workspace = projectGDB
arcpy.env.scratchWorkspace = projectGDB
arcpy.env.overwriteOutput = True
arcpy.AddMessage("Workspace is set to " + projectGDB)

#Where is Landcover.gdb located?
landcoverGDB = arcpy.GetParameterAsText(2)
if path == "#" or not landcoverGDB:
    landcoverGDB = "F:\\GIS\\TEST\\Landcover.gdb"

# Load NRI Datasets
building = landcoverGDB + "\\imperv_building"

#[script continues for another 200 lines]

Traceback (most recent call last): File "F:\GIS\Packaged\NRI_sumAcres.py", line 23, in print "Project geodatabase is " + projectGDB NameError: name 'projectGDB' is not defined

Generally speaking, I do not understand why the script ran without error when copied and pasted into the python window of ArcCatalog, but now is dysfunctional once added to a toolbox.

Answer 1

Don't manually concatenate paths. It leads to errors and makes your code non-portable to other OS's. Use os.path.join instead. For example, replace any instance of

projectGDB = path + projectName + ".gdb"

with :

 projectGDB = os.path.join(path, projectName + ".gdb")

I believe this will solve your problem, since "F:\GIS\TEST" doesn't end in a path separator, you're just sticking the projectName.gdb onto the end of it.

If that doesn't solve it, the line number where python is reporting the exception would help, as would sample output.

Answer 2

The problem may be in how you concatenate the variables to create projectGDB. What you're endiing up with for projectGDB is "F:\GIS\TESTTEST.gdb" Notice there's no slash between the path and the gdb name.

I'd suggest using os.path.join(path, projectName + '.gdb') to set projectGDB. Alternately, you could add a slash in front of projectName manually. Also, maybe print out the variable at different stages, see if you're getting what you want. And add some try/except blocks.

Answer 3

Here's a revised version of the first part of your script. Notice you don't even need projectGDB, at least to this stage. Untested, and written as a script, not a tool (except for the GetParameter calls). You should probably check if the path exists as well.

# Import arcpy module & other helpful
import arcpy, os, xlwt

# Name Project
ext = ".gdb"
projectName = arcpy.GetParameterAsText(0)
if projectName == "#" or not projectName:
    projectName = "TEST.gdb"

# make sure projectName has .gdb extension. Ideally, you'd test for invalid
# gdb names as well
if not projectName[-4:] == ext:
    projectName = projectName + ext

print('projectName is: {0}'.format(projectName))   # check that name is correct

# Create Project Folder
projPath = arcpy.GetParameterAsText(1) # renamed variable to avoid reserved word confusion
if projPath == "#" or not projPath:
    projPath = "F:\\GIS\\TEST"
arcpy.AddMessage("Folder path for project is " + projPath)
print('projPath is: {0}'.format(projPath))

# Create Project Geodatabase
try:
    arcpy.CreateFileGDB_management(projPath, projectName, "CURRENT")
except Exception as e:
    # simple error message
    print('Error creating filegdb {0}'.format(os.path.join(projPath, projectName)))
    print('Exception: {0}'.format(e.message))

Answer 4

Caitlin, here's a tool I created that does what you want, at least as far as your question goes. I haven't added validation, except to set default values, so you may want to do that. In particular, check that filePath exists in case the user manually types in a non-existent path. Note that they can browse to an existing folder, and create a new one. Setting default values and Required eliminates some of your checking code. Also, it would be more appropriate to use AddError than just print(), but this is a start.

import arcpy, sys

gdbName = arcpy.GetParameterAsText(0)
filePath = arcpy.GetParameterAsText(1)   # user able to set file path in tool

# check if filepath exists
if not os.path.exists(filePath):
    print('Path {0} does not exist.'.format(filePath)
    sys.exit()

try:
    arcpy.CreateFileGDB_management(filePath, gdbName)
except Exception as e:
    print('Error creating gdb {0} at {1}'.format(gdbName, filePath))
    print('Exception: {0}'.format(e.message))