Metadata-Version: 2.0
Name: hunter
Version: 1.0.2
Summary: Hunter is a flexible code tracing toolkit.
Home-page: https://github.com/ionelmc/python-hunter
Author: Ionel Cristian Mărieș
Author-email: contact@ionelmc.ro
License: BSD
Keywords: trace,tracer,settrace,debugger,debugging,code,source
Platform: UNKNOWN
Classifier: Development Status :: 5 - Production/Stable
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: BSD License
Classifier: Operating System :: Unix
Classifier: Operating System :: POSIX
Classifier: Operating System :: Microsoft :: Windows
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 2.6
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.3
Classifier: Programming Language :: Python :: 3.4
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: Implementation :: CPython
Classifier: Programming Language :: Python :: Implementation :: PyPy
Classifier: Topic :: Utilities
Classifier: Topic :: Software Development :: Debuggers
Requires-Dist: colorama
Requires-Dist: fields
Requires-Dist: six

========
Overview
========



Hunter is a flexible code tracing toolkit, not for measuring coverage, but for debugging, logging, inspection and other
nefarious purposes. It has a simple Python API and a convenient terminal API (see `Environment variable activation
<env-var-activation_>`_).

* Free software: BSD license

Installation
============

::

    pip install hunter

Documentation
=============

https://python-hunter.readthedocs.org/


Overview
========

The default action is to just print the code being executed. Example:

.. sourcecode:: python

    import hunter
    hunter.trace(module='posixpath')

    import os
    os.path.join('a', 'b')

Would result in::

    python2.7/posixpath.py:60    call      def join(a, *p):
    python2.7/posixpath.py:64    line          path = a
    python2.7/posixpath.py:65    line          for b in p:
    python2.7/posixpath.py:66    line              if b.startswith('/'):
    python2.7/posixpath.py:68    line              elif path == '' or path.endswith('/'):
    python2.7/posixpath.py:71    line                  path += '/' + b
    python2.7/posixpath.py:65    line          for b in p:
    python2.7/posixpath.py:72    line          return path
    python2.7/posixpath.py:72    return        return path
                                 ...       return value: 'a/b'

- or in a terminal:

.. image:: https://raw.githubusercontent.com/ionelmc/python-hunter/master/docs/simple-trace.png

You can have custom actions, like a variable printer - example:

.. sourcecode:: python

    import hunter
    hunter.trace(hunter.Q(module='posixpath', action=hunter.VarsPrinter('path')))

    import os
    os.path.join('a', 'b')

Would result in::

    python2.7/posixpath.py:60    call      def join(a, *p):
    python2.7/posixpath.py:64    line          path = a
                                 vars      path => 'a'
    python2.7/posixpath.py:65    line          for b in p:
                                 vars      path => 'a'
    python2.7/posixpath.py:66    line              if b.startswith('/'):
                                 vars      path => 'a'
    python2.7/posixpath.py:68    line              elif path == '' or path.endswith('/'):
                                 vars      path => 'a'
    python2.7/posixpath.py:71    line                  path += '/' + b
                                 vars      path => 'a/b'
    python2.7/posixpath.py:65    line          for b in p:
                                 vars      path => 'a/b'
    python2.7/posixpath.py:72    line          return path
                                 vars      path => 'a/b'
    python2.7/posixpath.py:72    return        return path
                                 ...       return value: 'a/b'

- or in a terminal:

.. image:: https://raw.githubusercontent.com/ionelmc/python-hunter/master/docs/vars-trace.png

You can give it a tree-like configuration where you can optionally configure specific actions for parts of the
tree (like dumping variables or a pdb set_trace):

    TODO: More examples.

.. _env-var-activation:

Environment variable activation
-------------------------------

For your convenience environment variable activation is available. Just run your app like this::


    PYTHONHUNTER="module='os.path'" python yourapp.py

On Windows you'd do something like::

    set PYTHONHUNTER=module='os.path'
    python yourapp.py

The activation works with a clever ``.pth`` file that checks for that env var presence and before your app runs does something
like this::

    from hunter import *
    trace(<whatever-you-had-in-the-PYTHONHUNTER-env-var>)

Note that Hunter is activated even if the env var is empty, eg: ``PYTHONHUNTER=""``.

Filtering DSL
-------------

Hunter supports a flexible query DSL, see the `introduction
<https://python-hunter.readthedocs.org/en/latest/introduction.html>`_.

Development
===========

To run the all tests run::

    tox


FAQ
===

Why not Smiley?
---------------

There's some obvious overlap with `smiley <https://pypi.python.org/pypi/smiley>`_ but there are few fundamental differences:

* Complexity. Smiley is simply over-engineered:

  * It's uses IPC and a SQL database.
  * It has a webserver. Lots of dependencies.
  * It uses threads. Side-effects and subtle bugs are introduced in your code.
  * It records everything. Tries to dump any variable. Often fails and stops working.

  Why do you need all that just to debug some stuff in a terminal? Simply put, it's a nice idea but the design choices work
  against you when you're already neck-deep into debugging your own code. In my experience Smiley has been very buggy and
  unreliable. Your mileage might way of course.

* Tracing long running code. This will make Smiley record lots of data, making it unusable.

  Now because Smiley records everything, you'd think it's better suited for short programs. But alas, if your program runs
  quickly then it's pointless to record the execution. You can just run it again.

  It seems there's only one situation where it's reasonable to use Smiley: tracing io-bound apps remotely. Those apps don't
  execute lots of code, they just wait on network so Smiley's storage won't blow out of proportion and tracing overhead might
  be acceptable.
* Use-cases. It seems to me Smiley's purpose is not really debugging code, but more of a "non interactive monitoring" tool.

In contrast, Hunter is very simple:

* Few dependencies.
* Low overhead (tracing/filtering code has an optional Cython extension).
* No storage. This simplifies lots of things.

  The only cost is that you might need to run the code multiple times to get the filtering/actions right. This means Hunter is
  not really suited for "post-mortem" debugging. If you can't reproduce the problem anymore then Hunter won't be of much help.

Why (not) coverage?
-------------------

For purposes of debugging `coverage <https://pypi.python.org/pypi/coverage>`_ is a great tool but only as far as "debugging
by looking at what code is (not) run". Checking branch coverage is good but it will only get you as far.

>From the other perspective, you'd be wondering if you could use Hunter to measure coverage-like things. You could do it but
for that purpose Hunter is very "rough": it has no builtin storage. You'd have to implement your own storage. You can do it
but it wouldn't give you any advantage over making your own tracer if you don't need to "pre-filter" whatever you're
recording.

In other words, filtering events is the main selling point of Hunter - it's fast (cython implementation) and the query API is
flexible enough.


Changelog
=========

1.0.1 (2015-12-24)
------------------

* Fix a compile issue with the MSVC compiler (seems it don't like the inline option on the ``fast_When_call``).

1.0.0 (2015-12-24)
------------------

* Implemented fast tracer and query objects in Cython. **MAY BE BACKWARDS INCOMPATIBLE**

  To force using the old pure-python implementation set the ``PUREPYTHONHUNTER`` environment variable to non-empty value.
* Added filtering operators: ``contains``, ``startswith``, ``endswith`` and ``in``. Examples:

  * ``Q(module_startswith='foo'`` will match events from ``foo``, ``foo.bar`` and ``foobar``.
  * ``Q(module_startswith=['foo', 'bar']`` will match events from ``foo``, ``foo.bar``, ``foobar``, ``bar``, ``bar.foo`` and ``baroo`` .
  * ``Q(module_endswith='bar'`` will match events from ``foo.bar`` and ``foobar``.
  * ``Q(module_contains='ip'`` will match events from ``lipsum``.
  * ``Q(module_in=['foo', 'bar']`` will match events from ``foo`` and ``bar``.
  * ``Q(module_regex=r"(re|sre.*)\b") will match events from ``re``, ``re.foobar``, ``srefoobar`` but not from ``repr``.

* Removed the ``merge`` option. Now when you call ``hunter.trace(...)`` multiple times only the last one is active.
  **BACKWARDS INCOMPATIBLE**
* Remove the `previous_tracer handling`. Now when you call ``hunter.trace(...)`` the previous tracer (whatever was in
  ``sys.gettrace()``) is disabled and restored when ``hunter.stop()`` is called. **BACKWARDS INCOMPATIBLE**
* Fixed ``CodePrinter`` to show module name if it fails to get any sources.

0.6.0 (2015-10-10)
------------------

* Added a ``clear_env_var`` option on the tracer (disables tracing in subprocess).
* Added ``force_colors`` option on ``VarsPrinter`` and ``CodePrinter``.
* Allowed setting the `stream` to a file name (option on ``VarsPrinter`` and ``CodePrinter``).
* Bumped up the filename alignment to 40 cols.
* If not merging then `self` is not kept as a previous tracer anymore.
  Closes `#16 <https://github.com/ionelmc/python-hunter/issues/16>`_.
* Fixed handling in VarsPrinter: properly print eval errors and don't try to show anything if there's an AttributeError.
  Closes `#18 <https://github.com/ionelmc/python-hunter/issues/18>`_.
* Added a ``stdlib`` boolean flag (for filtering purposes).
  Closes `#15 <https://github.com/ionelmc/python-hunter/issues/15>`_.
* Fixed broken frames that have "None" for filename or module (so they can still be treated as strings).
* Corrected output files in the ``install_lib`` command so that pip can uninstall the pth file.
  This only works when it's installed with pip (sadly, ``setup.py install/develop`` and ``pip install -e`` will still
  leave pth garbage on ``pip uninstall hunter``).

0.5.1 (2015-04-15)
------------------

* Fixed ``Event.globals`` to actually be the dict of global vars (it was just the locals).

0.5.0 (2015-04-06)
------------------

* Fixed ``And`` and ``Or`` "single argument unwrapping".
* Implemented predicate compression. Example: ``Or(Or(a, b), c)`` is converted to ``Or(a, b, c)``.
* Renamed the ``Event.source`` to ``Event.fullsource``.
* Added ``Event.source`` that doesn't do any fancy sourcecode tokenization.
* Fixed ``Event.fullsource`` return value for situations where the tokenizer would fail.
* Made the print function available in the ``PYTHONHUNTER`` env var payload.
* Added a __repr__ for ``Event``.

0.4.0 (2015-03-29)
------------------

* Disabled colors for Jython (contributed by Claudiu Popa in `#12 <https://github.com/ionelmc/python-hunter/pull/12>`_).
* Test suite fixes for Windows (contributed by Claudiu Popa in `#11 <https://github.com/ionelmc/python-hunter/pull/11>`_).
* Added an introduction section in the docs.
* Implemented a prettier fallback for when no sources are available for that frame.
* Implemented fixups in cases where you use action classes as a predicates.

0.3.1 (2015-03-29)
------------------

* Forgot to merge some commits ...

0.3.0 (2015-03-29)
------------------

* Added handling for internal repr failures.
* Fixed issues with displaying code that has non-ascii characters.
* Implemented better display for ``call`` frames so that when a function has decorators the
  function definition is shown (instead of just the first decorator).
  See: `#8 <https://github.com/ionelmc/python-hunter/issues/8>`_.

0.2.1 (2015-03-28)
------------------

* Added missing color entry for exception events.
* Added ``Event.line`` property. It returns the source code for the line being run.

0.2.0 (2015-03-27)
------------------

* Added color support (and ``colorama`` as dependency).
* Added support for expressions in ``VarsPrinter``.
* Breaking changes:

  * Renamed ``F`` to ``Q``. And ``Q`` is now just a convenience wrapper for ``Query``.
  * Renamed the ``PYTHON_HUNTER`` env variable to ``PYTHONHUNTER``.
  * Changed ``When`` to take positional arguments.
  * Changed output to show 2 path components (still not configurable).
  * Changed ``VarsPrinter`` to take positional arguments for the names.
* Improved error reporting for env variable activation (``PYTHONHUNTER``).
* Fixed env var activator (the ``.pth`` file) installation with ``setup.py install`` (the "egg installs") and
  ``setup.py develop``/``pip install -e`` (the "egg links").

0.1.0 (2015-03-22)
------------------

* First release on PyPI.


