text: import csv
  import os
  
  
  class Variables:
      HEADERS = ["Order", "Dataset", "Variable", "Label", "Data Type", "Length", "Significant Digits", "Format",
                 "KeySequence", "Mandatory", "CodeList", "Valuelist", "Origin", "Pages", "Method", "Predecessor",
                 "Role", "Comment"]
  
      def __init__(self, odmlib_mdv, data_path):
          self.mdv = odmlib_mdv
          self.path = data_path
          self.file_name = os.path.join(self.path, "variables.csv")
  
      def extract(self):
          with open(self.file_name, 'w', newline='') as f:
              writer = csv.writer(f, dialect="excel")
              writer.writerow(self.HEADERS)
              for ig in self.mdv.ItemGroupDef:
                  for ir in ig.ItemRef:
                      # assumes all ItemDefs are referenced by an ItemRef
                      ird = self._load_item_ref(ir)
                      idd = self._load_item_def(ir.ItemOID)
                      writer.writerow([ird["Order"], ig.Name, idd["Variable"], idd["Label"], idd["Data Type"], idd["Length"],
                                       idd["Significant Digits"], idd["Format"], ird["KeySequence"], ird["Mandatory"],
                                       idd["Codelist"], idd["Valuelist"], idd["Origin"], idd["Pages"], ird["Method"],
                                      idd["Predecessor"], ird["Role"], idd["Comment"]])
  
      def _load_item_ref(self, ir):
          ird = {}
          ird["Order"] = ir.OrderNumber
          ird["Mandatory"] = ir.Mandatory
          ird["KeySequence"] = ir.KeySequence
          ird["Method"] = ir.MethodOID
          ird["Role"] = ir.Role
          return ird
  
      def _load_item_def(self, item_oid):
          idd = {}
          it = self.mdv.find("ItemDef", "OID", item_oid)
          idd["Variable"] = it.Name
          idd["Data Type"] = it.DataType
          idd["Length"] = it.Length
          idd["Significant Digits"] = it.SignificantDigits
          idd["Format"] = it.DisplayFormat
          idd["Label"] = " ".join(it.Description.TranslatedText[0]._content.split())
          idd["Codelist"] = it.CodeListRef.CodeListOID if it.CodeListRef is not None else ""
          idd["Valuelist"] = it.ValueListRef.ValueListOID if it.ValueListRef else ""
          idd["Origin"] = it.Origin.Type if it.Origin else ""
          idd["Pages"] = it.Origin.DocumentRef[0].PDFPageRef[0].PageRefs \
              if it.Origin.DocumentRef and it.Origin.DocumentRef[0].PDFPageRef else ""
          idd["Predecessor"] = it.Origin.Description.TranslatedText[0]._content if it.Origin.Type == "Predecessor" else ""
          idd["Comment"] = it.CommentOID if it.CommentOID else ""
          return idd
  