fcUniqueVals.py

""" Generate a list of unique values for a field in a feature class

    Parameters:
    fc (str): Input feature class
    field (str): Field to find unique values for

    Returns:
    list: unique values in a field

"""

def uniqueVals(fc, field):
  valsList = []
  with arcpy.da.SearchCursor(fc, field) as cursor:
      for row in cursor:
          if row[0] not in valsList:
              valsList.append(row[0])
  if None in valsList:
      valsList.remove(None)
  valsList.sort()
  return valsList