Issue2105

Inconsistent conversion of PyObject to String in StdoutWrapper

Given some object o, executing

  print o

causes Jython to build a string representation of o to be displayed on the console.

The conversion is done differently depending on whether stdout/stderr are accessed through a PyFile or a PyFileWriter.

Jython uses PyFile by default, and results in an object's __str__ method being called.

PyFileWriter causes an object's __repr__ method to be called instead, which is inconsistent with CPython.

Running the test program using CPython (2.7.5 in this case) shows an object's __str__ method is called:

  $ python issue2105.py 
  str

Running with Jython 2.5.3 or the trunk also shows the __str__ method being called:

  $ jython issue2105.py 
  str

so out of the box, Jython is consistent with CPython.

But if stdout/stderr are changed to point to a Writer, so that Jython uses a PyFileWriter, for example by changing jython.java to:

  InteractiveConsole interp = new InteractiveConsole();
  interp.setOut(new PrintWriter(System.out));
  interp.setErr(new PrintWriter(System.err));

then the __repr__ method is called instead:

  $ jython issue2105.py 
  repr

On the trunk, the print method in StdoutWrapper calls printToFile if stdout is a PyFile, and calls printToFileWriter if stdout is a PyFileWriter.

printToFile does this:

  s = o.__str__().toString();

whereas printToFileWriter does this:

  s = o.toString();

which leads to the __repr__ method being called.

It's unclear why printToFileWriter doesn't also invoke the __str__ method.

Submitted Bitbucket pull request: https://bitbucket.org/jython/jython/pull-request/32/2105-fix-inconsistent-conversion-of/diff

Need to commit the outstanding PR attached to this bug, it's been too long!

Fixed as of https://hg.python.org/jython/rev/fbcbd5f9462b

Made it in 2.7.0 after all