Unicode Encoding Error in Python

When I was trying to print some unicode strings, an error occurred:

```
print(u'"Abstract":"' + printAbstract + u'",')
UnicodeEncodeError: 'ascii' codec can't encode character u'\u03b5' in position 513: ordinal not in range(128)
```

So it seems that strings are always encoded in ascii, even though I have declared them to be in unicode form by preceding `u`. However, the code was able to run in Python 2.7.10 Shell. So is there any convention that I should follow in my program or is it a bug?

Thanks :smile: