TBVaccine
TBVaccine is a utility that pretty-prints Python tracebacks. It automatically highlights lines you care about and deemphasizes lines you don't, and colorizes the various elements in a traceback to make it easier to parse.
Here are some screenshots. This is the before:
And this is the after:
If you add the hook or call TBVaccine in your code, it can also print all variables in each stack frame. That is, it turns this:
into this:
Installation
To install, use pip
:
pip install tbvaccine
You are done!
Global usage
You can have TBVaccine insert itself all up in your system and stick its tentacles in all your libraries, like a cute, useful Cthulhu. That way, every single Python traceback in your system will be pretty. Just set the TBVACCINE environment variable to 1, and you're done.
E.g. for bash:
export TBVACCINE=1
Or fish:
set -x TBVACCINE=1
Usage as a command-line utility
TBVaccine can be used from the command line several ways.:
python -m tbvaccine myscript.py
Or just pipe STDERR into it from the program you want to watch:
./myscript.py 2>&1 | tbvaccine
And all the tracebacks will now be pretty!
Usage as a Python library
There are various ways to use TBVaccine as a Python library.
Initialize it like so:
from tbvaccine import TBVaccine tbv = TBVaccine( code_dir="/my/code/dir", isolate=True )
code_dir
marks the directory we code about. Files under that directory that
appear in the traceback will be highlighted. If not passed, the current
directory, as returned by os.getcwd()
will be used.
If isolate
is False
, all lines are colorized, and code_dir
is
ignored.
If show_vars
is False
, variables will not be printed in each stack
frame.
To use it in an except
block:
from tbvaccine import TBVaccine try: some_stuff() except: print(TBVaccine().format_exc())
To make it the default way of printing tracebacks, use add_hook()
(which
also accepts any argument the TBVaccine
class does):
import tbvaccine tbvaccine.add_hook(isolate=False) 1 / 0
Bam! Instant pretty tracebacks.
Logging integration
You can integrate TBVaccine with logging like so:
class TbVaccineFormatter(logging.Formatter): def formatException(self, exc_info): return TBVaccine(isolate=True).format_exc() sh = logging.StreamHandler() sh.setFormatter(TbVaccineFormatter('[%(levelname)s] %(asctime)s : %(message)s', '%Y-%m-%d %H:%M:%S')) logger.addHandler(sh)
Epilogue
This library is still pretty new, please contribute patches if something doesn't work as intended, and also please tell your friends about it! Hopefully one day it will be implemented in the Python interpreters themselves.
-- Stavros