Issue2632

As reported in https://github.com/jythontools/jython/issues/90, an attempt to write non-ascii text via csv results in the infamous:

java.lang.IllegalArgumentException: java.lang.IllegalArgumentException: Cannot create PyString with non-byte value

Being old-school Python 2, this module thinks in bytes and leaves encoding to the user. By convention (?), the content of a CSV will be interpreted as UTF-8, so clients sensitive to the problem will supply encoded data. We reverse this philosophy in Python 3.

Almost certainly we should use a ByteBuffer where we presently use a StringBuilder since the file is in binary mode and the user should expect to encode the text before calling csv.writer.writerow().

Actually, non-ascii text is ok unless you supply it as a unicode. In that case, we buffer up the Java chars internally (UTF-16), and then try to treat this String as bytes, hence the error. If the client supplies a unicode object, I believe we should be encoding it with the default encoding. In the same circumstances, CPython says something like:

UnicodeEncodeError: 'ascii' codec can't encode character u'\xf6' in position 12: ordinal not in range(128)

So the StringBuilder can stay, but we ought to encode unicode objects as they arrive, if only so that we can fail the way CPython does.

Possibly fixed in https://hg.python.org/jython/rev/08978c4d1ab0

We now accept unicode objects and write and them with the default encoding (like CPython).