Edit File: trace.txt
: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 -C . somefile.py ... The above will execute :file:`somefile.py` and generate annotated listings of all Python modules imported during the execution into the current directory. Meta-options ^^^^^^^^^^^^ ``--help`` Display usage and exit. ``--version`` Display the version of the module and exit. Main options ^^^^^^^^^^^^ The ``--listfuncs`` option is mutually exclusive with the ``--trace`` and ``--count`` options . When ``--listfuncs`` is provided, neither ``--counts`` nor ``--trace`` are accepted, and vice versa. ``--count, -c`` Produce a set of annotated listing files upon program completion that shows how many times each statement was executed. See also ``--coverdir``, ``--file``, ``--no-report`` below. ``--trace, -t`` Display lines as they are executed. ``--listfuncs, -l`` Display the functions executed by running the program. ``--report, -r`` Produce an annotated list from an earlier program run that used the ``--count`` and ``--file`` option. Do not execute any code. ``--trackcalls, -T`` Display the calling relationships exposed by running the program. Modifiers ^^^^^^^^^ ``--file=<file>, -f`` Name of a file to accumulate counts over several tracing runs. Should be used with the ``--count`` option. ``--coverdir=<dir>, -C`` Directory where the report files go. The coverage report for ``package.module`` is written to file ``dir/package/module.cover``. ``--missing, -m`` When generating annotated listings, mark lines which were not executed with '``>>>>>>``'. ``--summary, -s`` When using ``--count`` or ``--report``, write a brief summary to stdout for each file processed. ``--no-report, -R`` Do not generate annotated listings. This is useful if you intend to make several runs with ``--count`` then produce a single set of annotated listings at the end. ``--timing, -g`` Prefix each line with the time since the program started. Only used while tracing. Filters ^^^^^^^ These options may be repeated multiple times. ``--ignore-module=<mod>`` Accepts comma separated list of module names. Ignore each of the named modules and its submodules (if it is a package). ``--ignore-dir=<dir>`` Ignore all modules and packages in the named directory and subdirectories (multiple directories can be joined by ``os.pathsep``). .. _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 name of the file from which to read stored count information. *outfile* is the name of the 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 :class:`Trace` object with the current tracing parameters. *cmd* must be a string or code object, suitable for passing into :func:`exec`. .. method:: Trace.runctx(cmd, globals=None, locals=None) Run *cmd* under control of the :class:`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. .. method:: Trace.results() Return a :class:`CoverageResults` object that contains the cumulative results of all previous calls to ``run``, ``runctx`` and ``runfunc`` for the given :class:`Trace` instance. Does not reset the accumulated trace results. .. class:: CoverageResults A container for coverage results, created by :meth:`Trace.results`. Should not be created directly by the user. .. method:: CoverageResults.update(other) Merge in data from another :class:`CoverageResults` object. .. method:: CoverageResults.write_results(show_missing=True, summary=False, coverdir=None) Write coverage results. Set *show_missing* to show lines that had no hits. Set *summary* to include in the output the coverage summary per module. *coverdir* specifies the directory into which the coverage result files will be output. If ``None``, the results for each source file are placed in its directory. .. A simple example demonstrating the use of the programming interface:: 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")
Back to File Manager