# How to change the number of decimal digits in arcmap in symbology

I'm using ArcMap 10.3. In symbology, there are 6 decimal digits for the different classes of the variable I'm presenting. I'd like to show only 3 decimal digits. I can edit the label and change the decimals manually for each class. Is there any faster way to do this for all classes in ArcMap 10.3?

• See the Q&A here as there is a very simple way of doing this. Nov 5, 2015 at 17:10
• @Hornbydd, yeah, that's a bit easier! The linked one should probably be closed (merged) and you can post your answer here.
– Paul
Nov 5, 2015 at 17:28
• @Paul, I don't know, I liked your code that will be useful to others (including me) and it is a solution... Mine is just simpler! ;) Also what did you use to record that moving image? Nov 5, 2015 at 17:42
• @Hornbydd, I wrote a `.bat` file based off this blog (it's just a few calls to `ffmpeg`). Drag a video file onto it and choose start and/or ending times. You can use any recording software, but I'm using Snagit.
– Paul
Nov 5, 2015 at 17:48

You can accomplish this with the `arcpy.mapping` module. The following should work as long as your symbology is `GraduatedColorsSymbology`. Just paste into the python window and run the function with your layer name and number of decimal places. Since it's using Python's built-in `round()` function, you can even use negative numbers.

``````def trunclabels(lyrname, n):

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

labels = lyr.symbology.classBreakLabels
#split the labels, cast to float, round, then join back together
lyr.symbology.classBreakLabels = ["{} - {}".format(*r)
for r in [[round(float(f), n)
for f in lab.split(" - ")]
for lab in labels]]

arcpy.RefreshTOC()
del mxd, df
``````

• do you know how to do this in ArcGIS Pro? When I try and use `trunclabels` I get the following error: `AttributeError: module 'arcpy.mp' has no attribute 'ListDataFrames'` Dec 15, 2017 at 16:44
• @MattA. Pro doesn't have the concept of data frames. You would instead list maps. See here for more info.
– Paul
Dec 20, 2017 at 16:50