Use six.unichr()

pybtex/bibtex/builtins.py

@@ -27,6 +27,8 @@ from __future__ import print_function, unicode_literals
 
 from functools import update_wrapper
 
+import six
+
 import pybtex.io
 from pybtex.bibtex import utils
 from pybtex.bibtex.exceptions import BibTeXError
@@ -206,7 +208,7 @@ def if_(i):
 def int_to_chr(i):
     n = i.pop()
     try:
-        char = unichr(n)
+        char = six.unichr(n)
     except ValueError:
         raise BibTeXError('%i passed to int.to.chr$', n)
     i.push(char)

pybtex/charwidths/make_charwidths.py

@@ -25,8 +25,11 @@
 """
 Make a table of character widths to use with bibtex width$ function.
 """
+
 from __future__ import print_function, unicode_literals
 
+import six
+
 
 def make_table(font_filename, output):
     import sys
@@ -74,7 +77,7 @@ def iter_charwidths(font_face):
     charcode, gindex = font_face.get_first_char()
     while gindex:
         font_face.load_glyph(gindex, FT_LOAD_NO_SCALE)
-        yield unichr(charcode), font_face.glyph.metrics.horiAdvance
+        yield six.unichr(charcode), font_face.glyph.metrics.horiAdvance
         charcode, gindex = font_face.get_next_char(charcode, gindex)