Heroku因“文件中非ASCII字符'\\ xe2'”错误而崩溃

Question

I'm trying to set up an Flask app on Heroku, but Heroku seems to keep on crashing. In the Heroku logs, it appears that Heroku is crashing due to this error:

SyntaxError: Non-ASCII character '\xe2' in file /app/app/range_parser.py on line 8, but no encoding declared;

Here are the following steps that I've taken to (attempt to) solve the problem:

• Set default Heroku encoding to UTF-8 via heroku config:add LANG=en_US.UTF-8
• Added # -*- coding: utf-8 -*- , # encoding=utf8 , and # coding: utf-8 to the header of the file
• Setting up runtime.txt file in root with runtime set to python-3.4.3
  • Note: after redeploying the app, the build still reads -----> Installing runtime (python-2.7.11) , so I'm not actually sure if heroku is actually registering the runtime.txt file. Is there a way to check?
• Messing around with the actual file in question. It appears that when I erase everything in the file but the header and have it return none , it's still giving me the same error on line 8 (even when there aren't even 8 lines in the file). This leads me to believe that the error probably stems from a runtime version/other error not directly related to the file itself.
• Lastly, deploying the app locally, through the run.py file, and through heroku local . This, surprisingly, works, again leading me to believe that the problem is with Heroku and not the file.

How do I resolve this problem?

Answer 1

My guess it the at line 8 of your app range_parser.py you have code that takes unicode instead of encoded utf-8 string and crashes the app. Check if you have some kind of text assignment, transformation or some kind of use and encode it to utf-8. Something like:

your_var.encode('utf-8') #if it is a unicode string

Answer 2

Figured out why Heroku was crashing.

My mistake was that even though I set up runtime.txt to build python-3.4.3, I forgot to commit and push the file, and git push heroku master to rebuild the runtime.

Not sure why the encoding error occurred in the first place, but with 3.4.3 it seems to be fixed.