Python 为不同语言的字符串生成XML，获取错误

我正在编写代码来生成包含不同语言字符串内容的XML。最初生成unicode时我遇到了一个错误，在开始时添加了setdefault命令，现在得到的是“attributeError:'str'对象没有属性'iter'python”。我试着寻找，但答案没有多大帮助

以下是回溯：

回溯（最近一次呼叫最后一次）：

请检查一下，让我知道我遗漏了什么

 File "oldgood_XliffGenerator.py", line 118, in <module>
    convertToXliff(filename)
  File "oldgood_XliffGenerator.py", line 47, in convertToXliff
    tree.write(destifilename, xml_declaration=True, encoding='utf-8')
  File "/usr/lib/python2.7/xml/etree/ElementTree.py", line 817, in write
    self._root, encoding, default_namespace
  File "/usr/lib/python2.7/xml/etree/ElementTree.py", line 877, in _namespaces
    for elem in iterate():
  File "/usr/lib/python2.7/xml/etree/ElementTree.py", line 477, in iter
    for e in e.iter(tag):
  File "/usr/lib/python2.7/xml/etree/ElementTree.py", line 477, in iter
    for e in e.iter(tag):
  File "/usr/lib/python2.7/xml/etree/ElementTree.py", line 477, in iter
    for e in e.iter(tag):
  File "/usr/lib/python2.7/xml/etree/ElementTree.py", line 477, in iter
    for e in e.iter(tag):
AttributeError: 'str' object has no attribute 'iter'

def convertToXliff(filename):
    if filename:
        if os.path.isfile(filename):
            valid=True
        else:
            print "Could not open "+filename
    else:
        print "no input"

    global fileLength
    root = ET.Element("file")

    global file
    file = ET.SubElement(root, "file")
    file.set("id", generatingLang)
    file.set("native", nativeLang)
    file.set("useAsLocale", setLocale)
    print "Reached stage1"
    datainp = fileRead(filename)
    RecurseObjects(datainp)
    destifilename = "testconvfile.xml"
    #Indent(root)

    tree = ET.ElementTree(root)
    tree.write(destifilename, xml_declaration=True, encoding='utf-8')