UnicodeError instead of UnicodeWarning

[Peter Otten]

Michael Ströder wrote:

> For tracking the cause of a UnicodeWarning I'd like to make the Python
> interpreter to raise an UnicodeError exception with full stack trace. Is
> there a short trick to achieve this?

You can control warning behaviour with the -W commandline option:

$ cat unicodewarning_demo.py
# -*- coding: utf-8 -*-

def g():
    "ä" == u"ä"

def f(n=3):
    if n:
        f(n-1)
    else:
        g()

if __name__ == "__main__":
    f()

$ python unicodewarning_demo.py
unicodewarning_demo.py:4: UnicodeWarning: Unicode equal comparison failed to 
convert both arguments to Unicode - interpreting them as being unequal
  "ä" == u"ä"
$ python -W error::UnicodeWarning unicodewarning_demo.py
Traceback (most recent call last):
  File "unicodewarning_demo.py", line 13, in <module>
    f()
  File "unicodewarning_demo.py", line 8, in f
    f(n-1)
  File "unicodewarning_demo.py", line 8, in f
    f(n-1)
  File "unicodewarning_demo.py", line 8, in f
    f(n-1)
  File "unicodewarning_demo.py", line 10, in f
    g()
  File "unicodewarning_demo.py", line 4, in g
    "ä" == u"ä"
UnicodeWarning: Unicode equal comparison failed to convert both arguments to 
Unicode - interpreting them as being unequal
$