This function maps the field types reported by Describe or Field to the keyword used by the Add Field tool.
def AddFieldType(tbl, field_name):
"""Determines keyword to create a field with the AddField tool of
the same type as the specified field.
Integer > "LONG", Float -> "SINGLE" etc
example
AddFieldType("test.dbf", "Shape_Leng")
"DOUBLE"
arcpy.AddField_management("test.dbf", "Shape_Len2",
AddFieldType("test.dbf", "Shape_Leng"))
"""
dtypes = {'OID': 'LONG', 'SmallInteger': 'SHORT', 'Integer': 'LONG',
'Double': 'DOUBLE', 'Single': 'FLOAT', 'String': 'TEXT',
'Date': 'DATE'}
fld_list = arcpy.Describe(tbl).Fields
ftype = [f.type for f in fld_list
if f.name.upper() == field_name.upper()]
if not ftype:
raise Exception("Field {} not found".format(field_name))
ftype = ftype[0]
try:
return dtypes[ftype]
except KeyError:
msg = "{}: field type {} not supported".format(field_name, ftype)
raise Exception(msg)
