Python checks whether a character is a valid XML character

the problems encountered in the project are recorded as follows to be useful to others.

  def   valid_xml_char_ordinal (c ):   ""   @ summary: check if the char is a valid XML character @ Param C: the character to be checked @ see: # http://www.w3.org/TR/2008/REC-xml-20081126/#charsets @ result: True/false  " "  return  (#  conditions ordered by presumed frequency  0x20 <= C <= 0xd7ff  or  C  in  (0x09, 0x0a, 0x0d )   or  0xe000 <= C <= 0 xfffd  or  0x10000 <= C <= 0x10ffff )  

Other illegal xml characters are encrypted by base64.CodeAs follows:

 Try  :  Import  XML. Sax. saxutils  Except  Importerror:  Raise Importerror ( "  Requires XML. Sax. saxutils package, pleas check if XML. Sax. saxutils is installed!  "  )  Import  Base64  Import Logginglogger = Logging. getlogger ( _ Name __  )  _ All __ = [ "  Escape  " , "  Unescape  "  ]  Def  Escape (data ):  """ @ Summary: Escape '&', '<', and '>' in a string of data. if the data is not ASCII, then encode in base64 @ Param data: the data to be processed @ return {"base64": True | false, "data": Data}  """      #  Check if all of the data is in ASCII code Is_base64 = False escaped_data = ""      Try  :  #  Data. Decode ("ASCII ")          If DataIs  None: Data = ""  Is_base64 = False  For C In  Data:  If   Not  Valid_xml_char_ordinal (c): is_base64 = True  Break          # Check if need base64 encode          If  Is_base64: logger. debug (  "  % S is not ascii-encoded string, so I will encode it in base64  "  )  #  Base64 encode Escaped_data = Base64.b64encode (data)  Else  :  # Check if the data shoshould be escaped to be stored in XML Escaped_data = XML. Sax. saxutils. Escape (data)  Except  Exception, E: logger. excpetion (E)  Return { "  Base64  "  : Is_base64,  "  Data  "  : Escaped_data}  Def Unescape (data, is_base64 = False ):  """  @ Summary: scape '& amp;', '& lt;', and' & gt; 'in a string of data. if base64 is true, then base64 decode will be processed first @ Param data: the data to be processed @ Param base64: Specify if the data is encoded by base64 @ result: unescaped data  """      #  Check if base64 Unescaped_data = Data  If  Is_base64:  Try : Unescaped_data = Base64.b64decode (data)  Except  Exception, EX: logger. debug (  "  Some excpetion occured when invoke b64decode  "  ) Logger. Error (Ex)  Print  Ex  Else  :  #  Unescape it Unescaped_data =XML. Sax. saxutils. Unescape (data)  Return Unescaped_data