/Doc/library/trace.rst
http://unladen-swallow.googlecode.com/ · ReStructuredText · 131 lines · 87 code · 44 blank · 0 comment · 0 complexity · 7739ed44aa45a49db28655233a0f19ca MD5 · raw file
- :mod:`trace` --- Trace or track Python statement execution
- ==========================================================
- .. module:: trace
- :synopsis: Trace or track Python statement execution.
- The :mod:`trace` module allows you to trace program execution, generate
- annotated statement coverage listings, print caller/callee relationships and
- list functions executed during a program run. It can be used in another program
- or from the command line.
- .. _trace-cli:
- Command Line Usage
- ------------------
- The :mod:`trace` module can be invoked from the command line. It can be as
- simple as ::
- python -m trace --count somefile.py ...
- The above will generate annotated listings of all Python modules imported during
- the execution of :file:`somefile.py`.
- The following command-line arguments are supported:
- :option:`--trace`, :option:`-t`
- Display lines as they are executed.
- :option:`--count`, :option:`-c`
- Produce a set of annotated listing files upon program completion that shows how
- many times each statement was executed.
- :option:`--report`, :option:`-r`
- Produce an annotated list from an earlier program run that used the
- :option:`--count` and :option:`--file` arguments.
- :option:`--no-report`, :option:`-R`
- Do not generate annotated listings. This is useful if you intend to make
- several runs with :option:`--count` then produce a single set of annotated
- listings at the end.
- :option:`--listfuncs`, :option:`-l`
- List the functions executed by running the program.
- :option:`--trackcalls`, :option:`-T`
- Generate calling relationships exposed by running the program.
- :option:`--file`, :option:`-f`
- Name a file containing (or to contain) counts.
- :option:`--coverdir`, :option:`-C`
- Name a directory in which to save annotated listing files.
- :option:`--missing`, :option:`-m`
- When generating annotated listings, mark lines which were not executed with
- '``>>>>>>``'.
- :option:`--summary`, :option:`-s`
- When using :option:`--count` or :option:`--report`, write a brief summary to
- stdout for each file processed.
- :option:`--ignore-module`
- Accepts comma separated list of module names. Ignore each of the named
- module and its submodules (if it is a package). May be given
- multiple times.
- :option:`--ignore-dir`
- Ignore all modules and packages in the named directory and subdirectories
- (multiple directories can be joined by os.pathsep). May be given multiple
- times.
- .. _trace-api:
- Programming Interface
- ---------------------
- .. class:: Trace([count=1[, trace=1[, countfuncs=0[, countcallers=0[, ignoremods=()[, ignoredirs=()[, infile=None[, outfile=None[, timing=False]]]]]]]]])
- Create an object to trace execution of a single statement or expression. All
- parameters are optional. *count* enables counting of line numbers. *trace*
- enables line execution tracing. *countfuncs* enables listing of the functions
- called during the run. *countcallers* enables call relationship tracking.
- *ignoremods* is a list of modules or packages to ignore. *ignoredirs* is a list
- of directories whose modules or packages should be ignored. *infile* is the
- file from which to read stored count information. *outfile* is a file in which
- to write updated count information. *timing* enables a timestamp relative
- to when tracing was started to be displayed.
- .. method:: Trace.run(cmd)
- Run *cmd* under control of the Trace object with the current tracing parameters.
- .. method:: Trace.runctx(cmd[, globals=None[, locals=None]])
- Run *cmd* under control of the Trace object with the current tracing parameters
- in the defined global and local environments. If not defined, *globals* and
- *locals* default to empty dictionaries.
- .. method:: Trace.runfunc(func, *args, **kwds)
- Call *func* with the given arguments under control of the :class:`Trace` object
- with the current tracing parameters.
- This is a simple example showing the use of this module::
- import sys
- import trace
- # create a Trace object, telling it what to ignore, and whether to
- # do tracing or line-counting or both.
- tracer = trace.Trace(
- ignoredirs=[sys.prefix, sys.exec_prefix],
- trace=0,
- count=1)
- # run the new command using the given tracer
- tracer.run('main()')
- # make a report, placing output in /tmp
- r = tracer.results()
- r.write_results(show_missing=True, coverdir="/tmp")