The ArcGIS Pro Python reference contains detailed information about every ArcPy module, function, and class provided with ArcGIS Pro; working with Python; and working with, and creating your own, geoprocessing tools in Python.

I'm having trouble trying to understand how field mapping works in ArcPy. I'm relatively new to Python. In the below example, I want to take a shapefile and append it to a feature class but I want to use the field map parameter so the fields from the shapefile go to the correct field names in the feature class. I successfully built this out in ModelBuilder and exported the Python script (see below) but so much of it doesn't make sense. For example, what are all these different codes... -1, 0, #, true, false, etc? There seems to be no documentation anywhere online on the meaning behind these codes. I read that I can use the fieldmapping() class as a parameter in this script but have been unable to incorporate that? If you know a much easier way (via python) to field map then using the above methods, I'm open to those suggestions. The code below is only a simple test that I created, so I can hopefully understand field mapping better but in the long run I want to this to be able to handle a LOT of fields from many different shapefiles. Source shapefile schema: Name, Code, Date Target feature class schema: Description, Num, Date # Import arcpy module import arcpy # Local variables: New_Shapefile_shp = "C:\\New_Shapefile.shp" New_Featureclass__2_ = New_Shapefile_shp New_Featureclass = "C:\\Target.gdb\\New_Featureclass" # Process: Append arcpy.Append_management("C:\\New_Shapefile.shp", New_Featureclass, "NO_TEST", "DESCRIPTION \"DESCRIPTION\" true true false 150 Text 0 0 ,First,#,C:\\New_Shapefile.shp,Name,-1,-1;NUM \"NUM\" true true false 4 Long 0 0 ,First,#,C:\\New_Shapefile.shp,Code,-1,-1;DATE \"DATE\" true true false 8 Date 0 0 ,First,#,C:\\New_Shapefile.shp,Date,-1,-1", "")

You are already using open-source. I've said that time and again to various audiences. The most committed Microsoft and Esri users will immediately balk, but it's easy to knock the objections down. Azure? Linux abounds. Esri? GDAL under the hood. And what does the "Py" in ArcPy stand for? Oh yeah, Python, the open-source programming language. You're already using open-source, even if you don't know it.