Removing layers and schema locks with ArcPy?

Question

I am creating a code that adds fields to a large set of shapefiles. I want to be able to open these shapefiles and edit the fields and then have them removed from the map document. I would like this because the amount of shapefiles that appear on the map document while the code is running is too large and ArcMap crashes.

Here is my code below:

for fc in arcpy.ListFeatureClasses():

    arcpy.AddField_management(fc, "C_TYPE", "TEXT") #add new field to each shapefile

    arcpy.AddField_management(fc, "C_UNIT", "TEXT") #add new field to each shapefile

    arcpy.AddField_management(fc, "INTERVAL", "LONG") #add new field to each shapefile

Below is what I want to remove:

Too many contours get accumulated in the document.

Is there any way I can add a piece of code that can remove this?

Answer 1

You can prevent, that layers are added to the map with the following:

from arcpy import env
env.addOutputsToMap = 0

If you need the layers in the view, you can clear the view with the following:

import arcpy
mxd = arcpy.mapping.MapDocument("CURRENT")
df = arcpy.mapping.ListDataFrames(mxd, "")[0]
lyrlist = arcpy.mapping.ListLayers(mxd, "", df)

for lyr in lyrlist:
    arcpy.Delete_management(lyr)

Be aware that only deleting a layer-object does not delete the data. If you use arcpy.Delete_management() with a featureclass (e.g. from arcpy.ListFeatureClasses()) the data will be deleted.