Set Data Driven Scale from Arcpy

Question

Is there a way to set the data driven scale from arcpy? Looking at the documentation for the DataDrivenPages class, it doesn't seem to be accessible from outside of ArcMap. The script I run within the current map document exports the maps as jpgs based on the Name and Page Number fields I set, and at the Data Driven Scale I specified. When I put the same script into a model (with the necessary adjustments made) and run it from ArcCatalog, I get the same result, except the maps are now at Best Fit scale, which is the default for data driven pages.

Answer 1

To ensure that the correct scale is used (in my case, the scales are valued stored in a field scale_field), the following code is added to the for loop which exports all the maps (the input document must have Data Driven Pages Enabled):

#some code here
mxd = arcpy.mapping.MapDocument(inputMapDoc)
df = arcpy.mapping.ListDataFrames(mxd)[0] #using the 1st data frame
for i in range(1, mxd.dataDrivenPages.pageCount + 1):
      mxd.dataDrivenPages.currentPageID = i
      df.scale = mxd.dataDrivenPages.pageRow.getValue(scale_field)

Answer 2

If you are running the script on a stored mxd you can set the scale properties in the extent tab of the data driven page setup. You can either use your current scale or use a field from the index layer that contains scale values.