[GIS] Using ArcPy to Rename Feature Class by Field

arcmaparcpyfeature-classfields-attributes

I made a little model and at the end I want to rename the feature class file to something based on the fields in that feature class. I want to rename that feature class by the date the data was collected (its a field in the FC) follow by an underscore then by the editor of the FC (which is also a field). The way our files are setup is the data is collected on the same date by one person. So there is no danger of having 2 editors to one file or 2 dates. I am just really new to Python.

I used it to do field calculations and have that understood fairly well. But I am trying to figure out the command to pull the field value and print it in the rename.

I have the stock python script for rename

# Name: Rename_Example2.py
# Description: Rename fileGDB feature class

# Import system modules
import arcpy
from arcpy import env

# Set workspace
env.workspace = "C:/workspace/test.gdb"

# Set local variables
in_data =  "test"
out_data = "testFC"
data_type = "FeatureClass"

# Execute Rename
arcpy.Rename_management(in_data, out_data, data_type)

How do I put the fields with the data into the "out_data"? I figure I have to collect it some how, maybe in the local variables? You don't need to write the script for me, but if you could point me to a solid source for commands and strings that would be great. I already checked out other threads and the python site.

https://docs.python.org/2/library/string.html#formatspec

It seems close to what I need but I am still not getting it.

Best Answer

You want ListFields: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//000v0000001p000000

in_data = "test"
out_data = "testFC"
fields = arcpy.ListFields(in_data)
for f in fields:
    print f.name

# join prefix and desired field names with an _
new_name = '_'.join([out_data, fields[0].name, fields[1].name])

# data_type is usually optional...
data_type = "FeatureClass"

arcpy.Rename_management(in_data, new_name, data_type)

Related Solutions

[GIS] Creating empty feature class in file geodatabase based on schema of ArcSDE feature class

Just use the CreateFeatureClass tool, passing the original feature class as the template argument. Grab the shape type from the Describe object of the input feature class.

Unlike the other answer, this won't copy a bunch of unnecessary records only to delete them right away.

import arcpy
arcpy.env.workspace= 'MyGDB.gdb'
fcs = arcpy.ListFeatureClasses()
output = "OutGDB.gdb"
for fc in fcs:
    geom = arcpy.Describe(fc).shapeType
    arcpy.CreateFeatureclass_management(output, fc, geom, fc, spatial_reference=fc)

UPDATE:

If you need to preserve domains/subtypes, then run Select_analysis using a generic where clause that will capture none of the records, like OBJECTID < 0:

import os, arcpy
arcpy.env.workspace= 'MyGDB.gdb'
fcs = arcpy.ListFeatureClasses()
output = "OutGDB.gdb"
wc = 'OBJECTID < 0'
for fc in fcs:
    fc_out = os.path.join(output, fc)
    arcpy.Select_analysis(fc, fc_out, wc)

This is far more efficient than copying all the records and then deleting them. I've yet to find an approach that will preserve editor tracking.

[GIS] SearchCursor() fails to read feature class

Confusingly, there are two different types of cursors: the "classic" cursors of Arc 10.0 and the arcpy.da cursors of Arc 10.1.

Arc 10.0 - "Classic" cursors

When using classic cursors (i.e. arcpy.SearchCursor) the cursor object is an iterable containing row objects. You need to use the getValue method to retrieve the data from the row.
The second parameter for arcpy.SearchCursor is your where clause, so you don't need the "*" parameter in there.
Your where clause is not set up properly, since Arc needs to have field names delimited by double quotes. To handle this with Python's use of quotes as string delimiters, you need to use the backslash escape character.

Here's a code sample with fixes applied:

fc = 'ShuttleStop_nextbus'
#List comprehension creates list of field names to read
fieldsList = [field.name for field in arcpy.ListFields("ShuttleStop_nextbus")]
cursor = arcpy.SearchCursor(fc, "\"NextBus_nu\" = '27837'")
for row in cursor:
    for field in fieldsList: #Iterate through field names
        print row.getValue(field) #Print value of this field for this row

Arc 10.1 - arcpy.da cursors

When using the new cursors in the data access module (i.e. arcpy.da.SearchCursor) you need to pass in a list of field names as the second parameter in the cursor constructor. This requires some more work up-front, but the resulting row objects are Python lists, which makes it easier to read data when iterating through cursor rows. arcpy.da.SearchCursor also has better performance than arcpy.SearchCursor, partially because it skips unimportant fields, especially geometry.
As before, your where clause is not set up properly, since Arc needs to have field names delimited by double quotes. To handle this with Python's use of quotes as string delimiters, you need to use the backslash escape character.

Here's a code sample with fixes applied:

fc = 'ShuttleStop_nextbus'
#List comprehension creates list of field names to read
fieldsList = [field.name for field in arcpy.ListFields("ShuttleStop_nextbus")]
cursor = arcpy.da.SearchCursor(fc, fieldsList , "\"NextBus_nu\" = '27837'")
for row in cursor:
    for cell in row: #Iterate through row, which is a Python list
        print cell #Print value of item in row list

Best Answer

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[GIS] Creating empty feature class in file geodatabase based on schema of ArcSDE feature class

[GIS] SearchCursor() fails to read feature class

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