My goal is to take a shapefile, change the length of one of the text fields, and save a new shapefile using arcpy.FeatureClassToFeatureClass_conversion. You can do it using the tool's interface, just add a shapefile to it and the fields are listed, right click on a field to change it's properties and change the field length, then save to a new shapefile.
But how to do that using code? I think you have to manipulate the field mapping to do it, but I cannot seem to find where you make the change for a particular field. So far I have:
>>> inshp = "c:/temp/test1.shp"
>>> fms = arcpy.FieldMappings()
>>> fm = fms.getFieldMap(0)
So how do I change the field length for the CITY_NAME field and save it back to the field mapping? Once that is done, I guess you put the field mapping back into the tool:
arcpy.FeatureClassToFeatureClass_conversion(inshp, "c:/temp", "test2.shp", "", field_mapping=fms)