mirror of https://github.com/python/cpython
Lots of small markup adjustments.
This commit is contained in:
parent
61a0a73d76
commit
fcd845a7ed
|
@ -2,31 +2,31 @@
|
||||||
High performance logging profiler}
|
High performance logging profiler}
|
||||||
|
|
||||||
\declaremodule{standard}{hotshot}
|
\declaremodule{standard}{hotshot}
|
||||||
|
\modulesynopsis{High performance logging profiler, mostly written in C.}
|
||||||
\moduleauthor{Fred L. Drake, Jr.}{fdrake@acm.org}
|
\moduleauthor{Fred L. Drake, Jr.}{fdrake@acm.org}
|
||||||
\sectionauthor{Anthony Baxter}{anthony@interlink.com.au}
|
\sectionauthor{Anthony Baxter}{anthony@interlink.com.au}
|
||||||
|
|
||||||
|
|
||||||
\versionadded{2.2}
|
\versionadded{2.2}
|
||||||
|
|
||||||
\modulesynopsis{High performance logging profiler, mostly written in C.}
|
|
||||||
|
|
||||||
|
This module provides a nicer interface to the \module{_hotshot} C module.
|
||||||
This module provides a nicer interface to the \code{_hotshot} C module.
|
|
||||||
Hotshot is a replacement for the existing \refmodule{profile} module. As it's
|
Hotshot is a replacement for the existing \refmodule{profile} module. As it's
|
||||||
written mostly in C, it should result in a much smaller performance impact
|
written mostly in C, it should result in a much smaller performance impact
|
||||||
than the existing profile module.
|
than the existing \refmodule{profile} module.
|
||||||
|
|
||||||
\begin{classdesc}{Profile}{logfile, \optional{, lineevents=0, linetimings=1}}
|
\begin{classdesc}{Profile}{logfile\optional{,
|
||||||
|
lineevents\code{=0}\optional{,
|
||||||
The profiler object. The argument \var{logfile} is the name of a log file
|
linetimings\code{=1}}}}
|
||||||
to use for logged profile data. The argument \var{lineevents} specifies whether
|
The profiler object. The argument \var{logfile} is the name of a log
|
||||||
to generate events for every source line, or just on function call/return. It
|
file to use for logged profile data. The argument \var{lineevents}
|
||||||
defaults to 0 (only log function call/return). The argument \var{linetimings}
|
specifies whether to generate events for every source line, or just on
|
||||||
specifies whether to record timing information. It defaults to 1 (store timing
|
function call/return. It defaults to \code{0} (only log function
|
||||||
|
call/return). The argument \var{linetimings} specifies whether to
|
||||||
|
record timing information. It defaults to \code{1} (store timing
|
||||||
information).
|
information).
|
||||||
|
|
||||||
\end{classdesc}
|
\end{classdesc}
|
||||||
|
|
||||||
|
|
||||||
\subsection{Profile Objects \label{hotshot-objects}}
|
\subsection{Profile Objects \label{hotshot-objects}}
|
||||||
|
|
||||||
Profile objects have the following methods:
|
Profile objects have the following methods:
|
||||||
|
@ -39,21 +39,18 @@ Add an arbitrary labelled value to the profile output.
|
||||||
Close the logfile and terminate the profiler.
|
Close the logfile and terminate the profiler.
|
||||||
\end{methoddesc}
|
\end{methoddesc}
|
||||||
|
|
||||||
%
|
|
||||||
\begin{methoddesc}{fileno}{}
|
\begin{methoddesc}{fileno}{}
|
||||||
Return the file descriptor of the profiler's log file.
|
Return the file descriptor of the profiler's log file.
|
||||||
\end{methoddesc}
|
\end{methoddesc}
|
||||||
|
|
||||||
\begin{methoddesc}{run}{cmd}
|
\begin{methoddesc}{run}{cmd}
|
||||||
Profile an exec-compatible string in the script environment.
|
Profile an \keyword{exec}-compatible string in the script environment.
|
||||||
|
The globals from the \refmodule[main]{__main__} module are used as
|
||||||
The globals from the \module{__main__} module are used as
|
|
||||||
both the globals and locals for the script.
|
both the globals and locals for the script.
|
||||||
\end{methoddesc}
|
\end{methoddesc}
|
||||||
|
|
||||||
\begin{methoddesc}{runcall}{func, *args, **keywords}
|
\begin{methoddesc}{runcall}{func, *args, **keywords}
|
||||||
Profile a single call of a callable.
|
Profile a single call of a callable.
|
||||||
|
|
||||||
Additional positional and keyword arguments may be passed
|
Additional positional and keyword arguments may be passed
|
||||||
along; the result of the call is returned, and exceptions are
|
along; the result of the call is returned, and exceptions are
|
||||||
allowed to propogate cleanly, while ensuring that profiling is
|
allowed to propogate cleanly, while ensuring that profiling is
|
||||||
|
@ -62,8 +59,7 @@ disabled on the way out.
|
||||||
|
|
||||||
|
|
||||||
\begin{methoddesc}{runctx}{cmd, globals, locals}
|
\begin{methoddesc}{runctx}{cmd, globals, locals}
|
||||||
Evaluate an exec-compatible string in a specific environment.
|
Evaluate an \keyword{exec}-compatible string in a specific environment.
|
||||||
|
|
||||||
The string is compiled before profiling begins.
|
The string is compiled before profiling begins.
|
||||||
\end{methoddesc}
|
\end{methoddesc}
|
||||||
|
|
||||||
|
@ -75,9 +71,10 @@ Start the profiler.
|
||||||
Stop the profiler.
|
Stop the profiler.
|
||||||
\end{methoddesc}
|
\end{methoddesc}
|
||||||
|
|
||||||
\subsection{Using hotshot data}
|
|
||||||
\declaremodule{standard}{hotshot.stats}
|
|
||||||
|
|
||||||
|
\subsection{Using hotshot data}
|
||||||
|
|
||||||
|
\declaremodule{standard}{hotshot.stats}
|
||||||
\modulesynopsis{Statistical analysis for Hotshot}
|
\modulesynopsis{Statistical analysis for Hotshot}
|
||||||
|
|
||||||
\versionadded{2.2}
|
\versionadded{2.2}
|
||||||
|
@ -91,16 +88,16 @@ of the \class{pstats.Stats} class.
|
||||||
\end{funcdesc}
|
\end{funcdesc}
|
||||||
|
|
||||||
\begin{seealso}
|
\begin{seealso}
|
||||||
\seemodule{profile}{The profile module's \class{Stats} class }
|
\seemodule{profile}{The \module{profile} module's \class{Stats} class}
|
||||||
\end{seealso}
|
\end{seealso}
|
||||||
|
|
||||||
|
|
||||||
\subsection{Example Usage \label{hotshot-example}}
|
\subsection{Example Usage \label{hotshot-example}}
|
||||||
|
|
||||||
Note that this example runs the python "benchmark" pystones. It can
|
Note that this example runs the python ``benchmark'' pystones. It can
|
||||||
take some time to run, and will produce large output files.
|
take some time to run, and will produce large output files.
|
||||||
|
|
||||||
\begin{verbatim}
|
\begin{verbatim}
|
||||||
|
|
||||||
>>> import hotshot, hotshot.stats, test.pystone
|
>>> import hotshot, hotshot.stats, test.pystone
|
||||||
>>> prof = hotshot.Profile("stones.prof")
|
>>> prof = hotshot.Profile("stones.prof")
|
||||||
>>> benchtime, stones = prof.runcall(test.pystone.pystones)
|
>>> benchtime, stones = prof.runcall(test.pystone.pystones)
|
||||||
|
@ -120,7 +117,4 @@ take some time to run, and will produce large output files.
|
||||||
.
|
.
|
||||||
.
|
.
|
||||||
.
|
.
|
||||||
|
|
||||||
\end{verbatim}
|
\end{verbatim}
|
||||||
|
|
||||||
|
|
||||||
|
|
|
@ -4,36 +4,36 @@
|
||||||
\declaremodule{standard}{timeit}
|
\declaremodule{standard}{timeit}
|
||||||
\modulesynopsis{Measure the execution time of small code snippets.}
|
\modulesynopsis{Measure the execution time of small code snippets.}
|
||||||
|
|
||||||
|
\versionadded{2.3}
|
||||||
\index{Benchmarking}
|
\index{Benchmarking}
|
||||||
\index{Performance}
|
\index{Performance}
|
||||||
|
|
||||||
\versionadded{2.3}
|
This module provides a simple way to time small bits of Python code.
|
||||||
|
It has both command line as well as callable interfaces. It avoids a
|
||||||
|
number of common traps for measuring execution times. See also Tim
|
||||||
|
Peters' introduction to the ``Algorithms'' chapter in the
|
||||||
|
\citetitle{Python Cookbook}, published by O'Reilly.
|
||||||
|
|
||||||
This module provides a simple way to time small bits of Python code. It has
|
The module defines the following public class:
|
||||||
both command line as well as callable interfaces. It avoids a number of
|
|
||||||
common traps for measuring execution times. See also Tim Peters'
|
|
||||||
introduction to the Algorithms chapter in the ``Python Cookbook'', published
|
|
||||||
by O'Reilly.
|
|
||||||
|
|
||||||
The module interface defines the following public class:
|
\begin{classdesc}{Timer}{\optional{stmt=\code{'pass'}
|
||||||
|
\optional{, setup=\code{'pass'}
|
||||||
\begin{classdesc}{Timer}{\optional{stmt='pass'
|
|
||||||
\optional{, setup='pass'
|
|
||||||
\optional{, timer=<timer function>}}}}
|
\optional{, timer=<timer function>}}}}
|
||||||
Class for timing execution speed of small code snippets.
|
Class for timing execution speed of small code snippets.
|
||||||
|
|
||||||
The constructor takes a statement to be timed, an additional statement used
|
The constructor takes a statement to be timed, an additional statement
|
||||||
for setup, and a timer function. Both statements default to 'pass'; the
|
used for setup, and a timer function. Both statements default to
|
||||||
timer function is platform-dependent (see the module doc string).
|
\code{'pass'}; the timer function is platform-dependent (see the
|
||||||
|
module doc string). The statements may contain newlines, as long as
|
||||||
|
they don't contain multi-line string literals.
|
||||||
|
|
||||||
To measure the execution time of the first statement, use the timeit()
|
To measure the execution time of the first statement, use the
|
||||||
method. The repeat() method is a convenience to call timeit() multiple
|
\method{timeit()} method. The \method{repeat()} method is a
|
||||||
times and return a list of results.
|
convenience to call \method{timeit()} multiple times and return a list
|
||||||
|
of results.
|
||||||
|
\end{classdesc}
|
||||||
|
|
||||||
The statements may contain newlines, as long as they don't contain
|
\begin{methoddesc}{print_exc}{\optional{file=\constant{None}}}
|
||||||
multi-line string literals.
|
|
||||||
|
|
||||||
\begin{methoddesc}{print_exc}{\optional{file=None}}
|
|
||||||
Helper to print a traceback from the timed code.
|
Helper to print a traceback from the timed code.
|
||||||
|
|
||||||
Typical use:
|
Typical use:
|
||||||
|
@ -48,20 +48,21 @@ Typical use:
|
||||||
|
|
||||||
The advantage over the standard traceback is that source lines in the
|
The advantage over the standard traceback is that source lines in the
|
||||||
compiled template will be displayed.
|
compiled template will be displayed.
|
||||||
|
The optional \var{file} argument directs where the traceback is sent;
|
||||||
The optional file argument directs where the traceback is sent; it defaults
|
it defaults to \code{sys.stderr}.
|
||||||
to \code{sys.stderr}.
|
|
||||||
\end{methoddesc}
|
\end{methoddesc}
|
||||||
|
|
||||||
\begin{methoddesc}{repeat}{\optional{repeat=3\optional{, number=1000000}}}
|
\begin{methoddesc}{repeat}{\optional{repeat\code{=3}\optional{,
|
||||||
|
number\code{=1000000}}}}
|
||||||
Call \method{timeit()} a few times.
|
Call \method{timeit()} a few times.
|
||||||
|
|
||||||
This is a convenience function that calls the \method{timeit()} repeatedly,
|
This is a convenience function that calls the \method{timeit()}
|
||||||
returning a list of results. The first argument specifies how many times to
|
repeatedly, returning a list of results. The first argument specifies
|
||||||
call \function{timeit()}. The second argument specifies the \code{number}
|
how many times to call \method{timeit()}. The second argument
|
||||||
argument for \function{timeit()}.
|
specifies the \var{number} argument for \function{timeit()}.
|
||||||
|
|
||||||
Note: it's tempting to calculate mean and standard deviation from the result
|
\begin{notice}
|
||||||
|
It's tempting to calculate mean and standard deviation from the result
|
||||||
vector and report these. However, this is not very useful. In a typical
|
vector and report these. However, this is not very useful. In a typical
|
||||||
case, the lowest value gives a lower bound for how fast your machine can run
|
case, the lowest value gives a lower bound for how fast your machine can run
|
||||||
the given code snippet; higher values in the result vector are typically not
|
the given code snippet; higher values in the result vector are typically not
|
||||||
|
@ -70,18 +71,19 @@ with your timing accuracy. So the \function{min()} of the result is
|
||||||
probably the only number you should be interested in. After that, you
|
probably the only number you should be interested in. After that, you
|
||||||
should look at the entire vector and apply common sense rather than
|
should look at the entire vector and apply common sense rather than
|
||||||
statistics.
|
statistics.
|
||||||
|
\end{notice}
|
||||||
\end{methoddesc}
|
\end{methoddesc}
|
||||||
|
|
||||||
\begin{methoddesc}{timeit}{\optional{number=1000000}}
|
\begin{methoddesc}{timeit}{\optional{number\code{=1000000}}}
|
||||||
Time \code{number} executions of the main statement.
|
Time \var{number} executions of the main statement.
|
||||||
|
This executes the setup statement once, and then
|
||||||
To be precise, this executes the setup statement once, and then returns the
|
returns the time it takes to execute the main statement a number of
|
||||||
time it takes to execute the main statement a number of times, as a float
|
times, measured in seconds as a float. The argument is the number of
|
||||||
measured in seconds. The argument is the number of times through the loop,
|
times through the loop, defaulting to one million. The main
|
||||||
defaulting to one million. The main statement, the setup statement and the
|
statement, the setup statement and the timer function to be used are
|
||||||
timer function to be used are passed to the constructor.
|
passed to the constructor.
|
||||||
\end{methoddesc}
|
\end{methoddesc}
|
||||||
\end{classdesc}
|
|
||||||
|
|
||||||
\subsection{Command Line Interface}
|
\subsection{Command Line Interface}
|
||||||
|
|
||||||
|
@ -97,55 +99,64 @@ where the following options are understood:
|
||||||
\item[-n N/--number=N] how many times to execute 'statement'
|
\item[-n N/--number=N] how many times to execute 'statement'
|
||||||
\item[-r N/--repeat=N] how many times to repeat the timer (default 3)
|
\item[-r N/--repeat=N] how many times to repeat the timer (default 3)
|
||||||
\item[-s S/--setup=S] statement to be executed once initially (default
|
\item[-s S/--setup=S] statement to be executed once initially (default
|
||||||
'pass')
|
\code{'pass'})
|
||||||
\item[-t/--time] use time.time() (default on all platforms but Windows)
|
\item[-t/--time] use \function{time.time()}
|
||||||
\item[-c/--clock] use time.clock() (default on Windows)
|
(default on all platforms but Windows)
|
||||||
|
\item[-c/--clock] use \function{time.clock()} (default on Windows)
|
||||||
\item[-v/--verbose] print raw timing results; repeat for more digits
|
\item[-v/--verbose] print raw timing results; repeat for more digits
|
||||||
precision
|
precision
|
||||||
\item[-h/--help] print a short usage message and exit
|
\item[-h/--help] print a short usage message and exit
|
||||||
\end{description}
|
\end{description}
|
||||||
|
|
||||||
A multi-line statement may be given by specifying each line as a separate
|
A multi-line statement may be given by specifying each line as a
|
||||||
statement argument; indented lines are possible by enclosing an argument in
|
separate statement argument; indented lines are possible by enclosing
|
||||||
quotes and using leading spaces. Multiple -s options are treated similarly.
|
an argument in quotes and using leading spaces. Multiple
|
||||||
|
\programopt{-s} options are treated similarly.
|
||||||
|
|
||||||
If -n is not given, a suitable number of loops is calculated by trying
|
If \programopt{-n} is not given, a suitable number of loops is
|
||||||
successive powers of 10 until the total time is at least 0.2 seconds.
|
calculated by trying successive powers of 10 until the total time is
|
||||||
|
at least 0.2 seconds.
|
||||||
|
|
||||||
The default timer function is platform dependent. On Windows, clock() has
|
The default timer function is platform dependent. On Windows,
|
||||||
microsecond granularity but time()'s granularity is 1/60th of a second; on
|
\function{time.clock()} has microsecond granularity but
|
||||||
Unix, clock() has 1/100th of a second granularity and time() is much more
|
\function{time.time()}'s granularity is 1/60th of a second; on \UNIX,
|
||||||
precise. On either platform, the default timer functions measures wall
|
\function{time.clock()} has 1/100th of a second granularity and
|
||||||
clock time, not the CPU time. This means that other processes running on
|
\function{time.time()} is much more precise. On either platform, the
|
||||||
the same computer may interfere with the timing. The best thing to do when
|
default timer functions measures wall clock time, not the CPU time.
|
||||||
accurate timing is necessary is to repeat the timing a few times and use the
|
This means that other processes running on the same computer may
|
||||||
best time. The -r option is good for this; the default of 3 repetitions is
|
interfere with the timing. The best thing to do when accurate timing
|
||||||
probably enough in most cases. On Unix, you can use clock() to measure CPU
|
is necessary is to repeat the timing a few times and use the best
|
||||||
time.
|
time. The \programopt{-r} option is good for this; the default of 3
|
||||||
|
repetitions is probably enough in most cases. On \UNIX, you can use
|
||||||
|
\function{time.clock()} to measure CPU time.
|
||||||
|
|
||||||
Note: there is a certain baseline overhead associated with executing a pass
|
\begin{notice}
|
||||||
statement. The code here doesn't try to hide it, but you should be aware of
|
There is a certain baseline overhead associated with executing a
|
||||||
it. The baseline overhead can be measured by invoking the program without
|
pass statement. The code here doesn't try to hide it, but you
|
||||||
arguments.
|
should be aware of it. The baseline overhead can be measured by
|
||||||
|
invoking the program without arguments.
|
||||||
|
\end{notice}
|
||||||
|
|
||||||
The baseline overhead differs between Python versions! Also, to fairly
|
The baseline overhead differs between Python versions! Also, to
|
||||||
compare older Python versions to Python 2.3, you may want to use python -O
|
fairly compare older Python versions to Python 2.3, you may want to
|
||||||
for the older versions to avoid timing SET_LINENO instructions.
|
use Python's \programopt{-O} option for the older versions to avoid
|
||||||
|
timing \code{SET_LINENO} instructions.
|
||||||
|
|
||||||
\subsection{Examples}
|
\subsection{Examples}
|
||||||
|
|
||||||
Here are two example sessions (one using the command line, one using the
|
Here are two example sessions (one using the command line, one using
|
||||||
module interface) that compare the cost of using \function{hasattr()}
|
the module interface) that compare the cost of using
|
||||||
vs. try/except to test for missing and present object attributes.
|
\function{hasattr()} vs. \keyword{try}/\keyword{except} to test for
|
||||||
|
missing and present object attributes.
|
||||||
|
|
||||||
\begin{verbatim}
|
\begin{verbatim}
|
||||||
\% timeit.py 'try:' ' str.__nonzero__' 'except AttributeError:' ' pass'
|
% timeit.py 'try:' ' str.__nonzero__' 'except AttributeError:' ' pass'
|
||||||
100000 loops, best of 3: 15.7 usec per loop
|
100000 loops, best of 3: 15.7 usec per loop
|
||||||
\% timeit.py 'if hasattr(str, "__nonzero__"): pass'
|
% timeit.py 'if hasattr(str, "__nonzero__"): pass'
|
||||||
100000 loops, best of 3: 4.26 usec per loop
|
100000 loops, best of 3: 4.26 usec per loop
|
||||||
\% timeit.py 'try:' ' int.__nonzero__' 'except AttributeError:' ' pass'
|
% timeit.py 'try:' ' int.__nonzero__' 'except AttributeError:' ' pass'
|
||||||
1000000 loops, best of 3: 1.43 usec per loop
|
1000000 loops, best of 3: 1.43 usec per loop
|
||||||
\% timeit.py 'if hasattr(int, "__nonzero__"): pass'
|
% timeit.py 'if hasattr(int, "__nonzero__"): pass'
|
||||||
100000 loops, best of 3: 2.23 usec per loop
|
100000 loops, best of 3: 2.23 usec per loop
|
||||||
\end{verbatim}
|
\end{verbatim}
|
||||||
|
|
||||||
|
|
Loading…
Reference in New Issue