xtraceback 0.2

Examples

As a context manager - the stdlib traceback module is monkey patched:

>>> import sys
>>> import traceback
>>> import xtraceback
>>>
>>> def some_func():
...     some_var = 2*2
...     raise Exception("exc")
>>>
>>> with xtraceback:
...     try:
...         some_func()
...     except:
...         traceback.print_exc(file=sys.stdout) #doctest: +ELLIPSIS
Traceback (most recent call last):
  File "<doctest README.rst[...]>", line 3, in <module>
    1 with xtraceback:
    2     try:
--> 3         some_func()
              g:some_func = <function some_func at 0x...>
              g:sys = <module 'sys' (built-in)>
              g:traceback = <module 'traceback' from='<stdlib>/traceback.pyc'>
              g:xtraceback = <package 'xtraceback' from='xtraceback'>
    4     except:
    5         traceback.print_exc(file=sys.stdout) #doctest: +ELLIPSIS
  File "<doctest README.rst[...]>", line 3, in some_func
    1 def some_func():
    2     some_var = 2*2
--> 3     raise Exception("exc")
          some_var = 4
Exception: exc

As a sys.excepthook:

>>> xtraceback.compat.install_excepthook()
>>> print sys.excepthook #doctest: +ELLIPSIS
<bound method TracebackCompat.print_exception of <xtraceback.tracebackcompat.TracebackCompat object at 0x...>>
>>> raise Exception("exc") #doctest: +ELLIPSIS
Traceback (most recent call last):
  File "<stdlib>/doctest.py", line 1231, in __run
    compileflags, 1) in test.globs
  File "<doctest README.rst[...]>", line 1, in <module>
    raise Exception("exc") #doctest: +ELLIPSIS
Exception: exc

By itself:

>>>
>>> try:
...     raise Exception("exc")
... except:
...     xtb = xtraceback.XTraceback(*sys.exc_info())
...     print "".join(xtb.format_exception()) #doctest: +ELLIPSIS
Traceback (most recent call last):
  File "<doctest README.rst[...]>", line 2, in <module>
    1 try:
--> 2     raise Exception("exc")
          g:some_func = <function some_func at 0x...>
          g:sys = <module 'sys' (built-in)>
          g:traceback = <module 'traceback' from='<stdlib>/traceback.pyc'>
          g:xtraceback = <package 'xtraceback' from='xtraceback'>
    3 except:
    4     xtb = xtraceback.XTraceback(*sys.exc_info())
    5     print "".join(xtb.format_exception()) #doctest: +ELLIPSIS
Exception: exc
<BLANKLINE>

In a python startup file:

if __name__ == "__main__":
    import xtraceback
    xtraceback.compat.install_excepthook()

Then tell python to use the startup file:

export PYTHONSTARTUP=/path/to/startup.py

Configuration

Options are passed as keyword arguments to the XTraceback constructor.

• offset=0 - Traceback offset

• limit=None - Traceback limit

• context=5 - Number of lines of context to show

• show_args=True - Show frame args

• show_locals=True - Show line locals

• show_globals=False - Show globals

• qualify_method_names=True - Qualify method names with the name of the owning class

• shorten_filenames=True - Shorten filenames where possible

• color=None - Whether to use color output

Installation

The package is on PyPI:

pip install xtraceback

Nose plugin

The nose plugin is enabled with the –with-xtraceback flag. See nose –help for other options.