Fix for issue #50, to ignore errors on shiftjis encoding

pyqrcode/__init__.py

@@ -325,6 +325,11 @@ def next_byte(b):
             #characters. Hence, the resulting mode should not be kanji.
             #This is not an error.
             pass
+        except LookupError:
+            #This occurs if the host Python does not support Shift JIS kanji
+            #encoding. Hence, the resulting mode should not be kanji.
+            #This is not an error.
+            pass
 
         #All of the other attempts failed. The content can only be binary.
         return 'binary', encoding

tests/test_issue50.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+"""\
+Tests against <https://github.com/mnooner256/pyqrcode/issues/50>
+"""
+from __future__ import unicode_literals
+from nose.tools import eq_
+import pyqrcode
+
+
+class FakeString(str):
+    '''
+    Create a mock class that *acts* like a string as far as needed for the
+    QRCode constructor, but raises an exception in case shiftjis encoding is
+    used on its value.
+
+    This mimics the behaviour of Python on an environment where this codec is
+    not installed.
+    '''
+    def __new__(cls, *more):
+        return str.__new__(cls, *more)
+
+    def encode(self, encoding=None, errors=None):
+        if encoding == 'shiftjis':
+            raise LookupError("unknown encoding: shiftjis")
+        return self.encode(encoding, errors)
+
+
+def test_constructing_without_shiftjis_encoding_available():
+    content = FakeString("t123456789")
+    code = pyqrcode.create(content, error="Q")
+    eq_(code.mode, 'binary')