expat ParseFile expects bytes, not string #60930

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1. mdehoon commented on Dec 19, 2012

   

   mdehoonmannequin

   on Dec 19, 2012

   MannequinAuthor

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   The expat parser in xml.parsers.expat has a Parse method and a ParseFile method. The Parse method parses a string, however the ParseFile method wants bytes.

   This is a minimal example of the Parse method:

   >> import xml.parsers.expat
   >> p = xml.parsers.expat.ParserCreate()
   >> p.Parse('<?xml version="1.0"?>')

   which runs fine. Note that argument to p.Parse is a string, not bytes.

   This is the corresponding example of ParseFile:

   >> import xml.parsers.expat
   >> handle = open("test.xml")
   >> p = xml.parsers.expat.ParserCreate()
   >> p.ParseFile(handle)

   where the file test.xml only contains <?xml version="1.0"?>
   This gives an error:

   Traceback (most recent call last):
     File "<stdin>", line 1, in <module>
   TypeError: read() did not return a bytes object (type=str)

   Opening the file test.xml in binary raises an Error:

   >>> import xml.parsers.expat
   >>> handle = open("test.xml", "rb")
   >>> p = xml.parsers.expat.ParserCreate()
   >>> p.ParseFile(handle)
   Traceback (most recent call last):
     File "<stdin>", line 1, in <module>
   xml.parsers.expat.ExpatError: no element found: line 2, column 0

   suggesting that in reality, the expat Parser needs a string, not bytes.
   (the same error appears with a more meaningful XML file).

   I would expect that both Parse and ParseFile accept strings, but not bytes.
2. mdehoon

   added

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   on Dec 19, 2012
3. BreamoreBoy commented on Jul 13, 2014

   

   BreamoreBoymannequin

   on Jul 13, 2014

   Mannequin

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   @michiel I'm sorry about the delay in replying to you. I can confirm the same behaviour in 3.4.1 on 3.5.0a0 on Windows 7.
4. sbardeau commented on Oct 14, 2014

   

   sbardeaumannequin

   on Oct 14, 2014

   Mannequin

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   Same problem here with:
   Python 3.4.1 (default, Jul 30 2014, 14:02:54)
   [GCC 4.4.7 20120313 (Red Hat 4.4.7-3)] on linux

   What is unclear to me if this is a bug or a feature. In particular, as described here http://stackoverflow.com/questions/1179305/expat-parsing-in-python-3, one can open the xml file as binary to solve the issue. But is this /really/ intended? Opening standard ASCII xml files as binaries!?
5. iritkatriel commented on Nov 28, 2021

   

   iritkatriel

   on Nov 28, 2021

   Member

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   Reproduced on 3.11.

   👍React with 👍1Reacted by Sebastian Feustel
6. iritkatriel

   added

   stdlibStandard Library Python modules in the Lib/ directoryStandard Library Python modules in the Lib/ directory

   3.9 (EOL)end of lifeend of life

   3.10 (EOL)end of lifeend of life

   3.11only security fixesonly security fixes

   on Nov 28, 2021
7. ezio-melotti

   transferred this issue fromon Apr 10, 2022
8. serhiy-storchaka

   added

   topic-XML

   on May 10, 2022
9. serhiy-storchaka

   closed this as completedin #156822on Sep 2, 2026
10. serhiy-storchaka commented on Sep 2, 2026

    

    serhiy-storchaka

    on Sep 2, 2026

    Member

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    ParseFile() supports only binary files, which is now stated explicitly in the documentation (gh-156821, GH-156822). Adding support of text files (if anybody needs this) is a separate issue.