Turning off all layers in MXD using ArcPy?

Question

I tried this standalone script to turn off all layers in the MXD:

print "This script turns off the following layers:"
    try:
        arcpy 
    except NameError:
        import arcpy
    mxd = arcpy.mapping.MapDocument(r"PATH")
    for lyr in arcpy.mapping.ListLayers(mxd):
        print lyr.name
        lyr.visible = False
    mxd.save

It is adapted from the script mentioned for the Python window here:

https://geonet.esri.com/thread/16415

The standalone one I created for IDLE from this, above, did not affect the visibility status of any layers when I opened the MXD afterward to check. This is strange because running the same script within the Python window turned off all the layers for me.

Any clues?

Answer 1

The reason why this code is failing is down to you missing () off the save method on your MXD, so you were not saving your changes. This code worked for me

import arcpy
print "This script turns off the following layers:"
mxd = arcpy.mapping.MapDocument(r"C:\Scratch\newcode.mxd")
for lyr in arcpy.mapping.ListLayers(mxd):
    print lyr.name
    lyr.visible = False

mxd.save()
del mxd