Issue with Unicode in Python 2

[goerlitz]

I'm trying to annotate some Unicode strings. But following example throws errors.

Case 1: Passing Unicode strings.

from pycorenlp import StanfordCoreNLP
nlp = StanfordCoreNLP('http://localhost:9000/')
text = u'Köln is a city in Germany.'
print(nlp.annotate(text))

throws

AssertionErrorTraceback (most recent call last)
/home/jovyan/work/python/pycorenlp/corenlp.py in annotate(self, text, properties)
---> 11         assert isinstance(text, str)

AssertionError:

because it's a string of type 'unicode' in Python 2.

Case 2: Passing encoded Unicode strings:

from pycorenlp import StanfordCoreNLP
nlp = StanfordCoreNLP('http://localhost:9000/')
text = u'Köln is a city in Germany.'.encode('utf-8')
print(nlp.annotate(text))

throws

UnicodeDecodeErrorTraceback (most recent call last)
/home/jovyan/work/python/pycorenlp/corenlp.py in annotate(self, text, properties)
---> 25         data = text.encode()

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 1: ordinal not in range(128)

because the string has already been encoded and cannot be encoded again.

These two lines of code in the error messages were both introduced in #6 in May 2016 to fix some Unicode issues.
However, is seems the explicit encoding in line 25 is not required anymore, because if removed case 2 works perfectly (both in Python 2 and Python 3).

Note also that encoding issues were fixed in CoreNLP in October 2016 (stanfordnlp/CoreNLP#270).

[goerlitz]

I have to correct myself. The characters encoding in Python 3 will be broken again if text.encode() is removed. So this string problem seems to be caused by one of the incompatible changes in Python 3.

If found out that a different wrapper implementation uses this piece of code to fix the issue:

if sys.version_info.major >= 3:
    text = text.encode('utf-8')