Skipping Non-spatial Data in For Loop

Question

I'm working in ArcMap 10.3, and I have a script that searches through all the folder and files in a directory using arcpy.da.Walk, grabs any file containing a key word, and copies it over to new a gdb based on whether it is a point, line, or polygon.

In this case I'm only grabbing vector files, either shapefiles or feature classes.

The problem is that it gets held up when it encounters non-spatial files, like a .jpg, because I'm using desc.shapeType on each file. What I'd like to know is, is there a way to quickly determine if a file is spatial or not, besides adding in some statements about its file extension (i.e.if fc.endswith(".jpg"):?

Answer 1

You can use the arcpy.ListFeatureClasses to accomplish this there is a type option. Documentation below

http://resources.arcgis.com/en/help/main/10.1%20/index.html#//002z00000011000000

I'm assuming your question is vague for a reason and not poorly written. There are going to have to be some assumptions on my end and the answer can only be psuedo code, because you have not stated what the file types meet your criteria for conversion, and if there are multiple data types. If there are you will have to expand this answer with if/else clause in order to ultimately perform Do something or provide your script in the OP. The da.walk method is a hybrid of os.walk and includes a data type.

I think this may be a misunderstanding of what a feature classes is. A more detailed discussion on the topic can be found here on another thread but the basics:

The definition of feature class is a "homogeneous collections of common features, each having the same spatial representation, such as points, lines, or polygons, and a common set of attribute columns, for example, a line feature class for representing road centerlines."

Feature classes are stored in a container be it a shapefile, DWG, or DB. For high level thinking a shapefile can be thought of as a single feature class while a gdb is many features classes. You script is going to have to target the container that holds the feature class (shapefile or some other container it does not matter) and perform the action on the contents. You can use arcpy.da.Walk to target those containers that meet a certain datatype criteria (provided its an ESRI compatible container).

for dirpath, dirnames, filenames in arcpy.da.Walk(workspace,
                                                  topdown=True,
                                                  datatype="featureclass"):
    for filename in filenames:
        arrcpy.whatever()

Another Example:

As per the ESRI documentation you can query based on dataypes and filetype

for dirpath, dirnames, filenames in arcpy.da.Walk(workspace,
    datatype='FeatureClass', type=['Polygon', 'Polyline']):  

Here is an example of using da.walk on a data tree

''' 
Created on Aug 25, 2014 
@author: PeterW 
'''  

# Import system modules  
import arcpy  
import os  

# Set current workspace  
workspace = r'E:\Projects\Projects14\H103342\test2.gdb'  
arcpy.env.workspace = workspace  

# Set environment settings  
arcpy.env.overwriteOutput = True  

# Create list of Feature Classes in each Feature Dataset  
fcs = []  

# Iterate through each Feature Dataset within the File Geodatabase  
for dirpath, dirnames, filenames in arcpy.da.Walk(workspace, datatype = "FeatureDataset"):  
    for filename in filenames:  
        print filename