How to run the Calculate Field using ArcPy?

Question

I have an issue in executing the Calculate field command in Python (ArcPy). I couldn't find any related resources or helpful descriptions regarding this. I hope somebody could help me with this.

inFeatures = r"H:\Python Projects\PycharmProjects\ArcPy\Test_Output\Trial_out.gdb\Trail_Data_A.shp"

arcpy.CalculateField_management(inFeatures, 'ObjArt_Ken', '!AttArt_Ken!'.split('_')[0])
arcpy.CalculateField_management(inFeatures, 'Wert', '!AttArt_Ken!'.split('_')[-1])

The error i am getting when I run the command is

arcgisscripting.ExecuteError: Error during execution. Parameters are invalid.
ERROR 000989: The CalculateField tool cannot use VB expressions for services.
Error while executing (CalculateField).

I am using ArcGIS Pro 2.8 and Python 2.7

JohannesLindner · Answer

Seems like you saved the unicode symbol and the double quotes as actual text.

Try this:

# define a function that will convert 'u"1234_5678"' to '1234_5678'
# CalculateField needs it as string
code_block = """
def clean_up(text_value):
    if text_value.startswith('u"'):
        text_value = text_value[1:]  # remove unicode symbol
    return text_value.replace('"', '')  # remove double quotes
"""

func_1 = "clean_up(!AttArt_Ken!).split('_')[0]"  # without single quotes around the field name!
field_1 = "ObjArt_Ken"

func_2 = "clean_up(!AttArt_Ken!).split('_')[1]" # without single quotes around the field name!
field_2 = "Wert"

arcpy.AddField_management(inTable, field_1, "TEXT".encode('utf-8'))
arcpy.CalculateField_management(inTable, field_1, func_1, "PYTHON_9.3", code_block)

arcpy.AddField_management(inTable, field_2, "TEXT".encode('utf-8'))
arcpy.CalculateField_management(inTable, field_2, func_2, "PYTHON_9.3", code_block)

MalikaCheema · Answer

I found a working output for the above mentioned question

inTable = r'H:\Python Projects\PycharmProjects\ArcPy\Test_Output\Trial_out.gdb\Trail_Data_A.shp'

func_1 = "'!AttArt_Ken!'.split('_')[0]"
field_1 = "ObjArt_Ken"

func_2 = "'!AttArt_Ken!'.split('_')[1]"
field_2 = "Wert"

arcpy.AddField_management(inTable, field_1, "TEXT".encode('utf-8'))
arcpy.CalculateField_management(inTable, field_1, func_1, "PYTHON_9.3")

arcpy.AddField_management(inTable, field_2, "TEXT".encode('utf-8'))
arcpy.CalculateField_management(inTable, field_2, func_2, "PYTHON_9.3")

But a problem still exists such that the output (After split function) is like |ObjArt_Ken|Wert| |:---|:---| |u"31001|1001"|

I still couldn't figure out a way to remove the unicode or the '"' symbol from the desired output

Luke_Pinner · Answer

Your file path is r"...\Trial_out.gdb\Trail_Data_A.shp"

This will never work.  You appear to have saved a shapefile into a .gdb folder that while it is just a folder to Windows, is not treated as a folder by ArcGIS, but as a file geodatabase. ArcGIS does not recognise non-file geodatabase data that is stored in the .gdb folder.

* Move your Trail_Data_A.shp, Trail_Data_A.dbf, Trail_Data_A.shx, Trail_Data_A.* files out of the Trial_out.gdb folder to a normal folder.
* If you want a file geodatabase feature class, use ArcGIS to export your shapefile to the database.