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<TITLE>The Stats Class -- Python library reference</TITLE>
Prev: <A HREF="../r/reference_manual" TYPE="Prev">Reference Manual</A>
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<H2>9.5.1. The <CODE>Stats</CODE> Class</H2>
<DL><DT><B>strip_dirs</B> () -- Method on Stats<DD>
This method for the <CODE>Stats</CODE> class removes all leading path information
from file names. It is very useful in reducing the size of the
printout to fit within (close to) 80 columns. This method modifies
the object, and the stripped information is lost. After performing a
strip operation, the object is considered to have its entries in a
``random'' order, as it was just after object initialization and
loading. If <CODE>strip_dirs()</CODE> causes two function names to be
indistinguishable (i.e., they are on the same line of the same
filename, and have the same function name), then the statistics for
these two entries are accumulated into a single entry.
</DL>
<DL><DT><B>add</B> (<VAR>filename</VAR>[, ...]) -- Method on Stats<DD>
This method of the <CODE>Stats</CODE> class accumulates additional profiling
information into the current profiling object. Its arguments should
refer to filenames created by the corresponding version of
<CODE>profile.run()</CODE>. Statistics for identically named (re: file,
line, name) functions are automatically accumulated into single
function statistics.
</DL>
<DL><DT><B>sort_stats</B> (<VAR>key</VAR>[, ...]) -- Method on Stats<DD>
This method modifies the <CODE>Stats</CODE> object by sorting it according to the
supplied criteria. The argument is typically a string identifying the
basis of a sort (example: <CODE>"time"</CODE> or <CODE>"name"</CODE>).
<P>
When more than one key is provided, then additional keys are used as
secondary criteria when the there is equality in all keys selected
before them. For example, sort_stats('name', 'file') will sort all
the entries according to their function name, and resolve all ties
(identical function names) by sorting by file name.
<P>
Abbreviations can be used for any key names, as long as the
abbreviation is unambiguous. The following are the keys currently
defined:
<P>
<DL>
<DT><I>Valid Arg</I><DD> --- <I>Meaning</I>
<P>
<DT><CODE>"calls"</CODE><DD>call count
<DT><CODE>"cumulative"</CODE><DD>cumulative time
<DT><CODE>"file"</CODE><DD>file name
<DT><CODE>"module"</CODE><DD>file name
<DT><CODE>"pcalls"</CODE><DD>primitive call count
<DT><CODE>"line"</CODE><DD>line number
<DT><CODE>"name"</CODE><DD>function name
<DT><CODE>"nfl"</CODE><DD>name/file/line
<DT><CODE>"stdname"</CODE><DD>standard name
<DT><CODE>"time"</CODE><DD>internal time
</DL>
Note that all sorts on statistics are in descending order (placing
most time consuming items first), where as name, file, and line number
searches are in ascending order (i.e., alphabetical). The subtle
distinction between <CODE>"nfl"</CODE> and <CODE>"stdname"</CODE> is that the
standard name is a sort of the name as printed, which means that the
embedded line numbers get compared in an odd way. For example, lines
3, 20, and 40 would (if the file names were the same) appear in the
string order 20, 3 and 40. In contrast, <CODE>"nfl"</CODE> does a numeric
compare of the line numbers. In fact, <CODE>sort_stats("nfl")</CODE> is the
same as <CODE>sort_stats("name", "file", "line")</CODE>.
<P>
For compatibility with the old profiler, the numeric arguments
`<SAMP>-1</SAMP>', `<SAMP>0</SAMP>', `<SAMP>1</SAMP>', and `<SAMP>2</SAMP>' are permitted. They are
interpreted as <CODE>"stdname"</CODE>, <CODE>"calls"</CODE>, <CODE>"time"</CODE>, and
<CODE>"cumulative"</CODE> respectively. If this old style format (numeric)
is used, only one sort key (the numeric key) will be used, and
additional arguments will be silently ignored.
</DL>
<DL><DT><B>reverse_order</B> () -- Method on Stats<DD>
This method for the <CODE>Stats</CODE> class reverses the ordering of the basic
list within the object. This method is provided primarily for
compatibility with the old profiler. Its utility is questionable
now that ascending vs descending order is properly selected based on
the sort key of choice.
</DL>
<DL><DT><B>print_stats</B> (<VAR>restriction</VAR>[, ...]) -- Method on Stats<DD>
This method for the <CODE>Stats</CODE> class prints out a report as described
in the <CODE>profile.run()</CODE> definition.
<P>
The order of the printing is based on the last <CODE>sort_stats()</CODE>
operation done on the object (subject to caveats in <CODE>add()</CODE> and
<CODE>strip_dirs())</CODE>.
<P>
The arguments provided (if any) can be used to limit the list down to
the significant entries. Initially, the list is taken to be the
complete set of profiled functions. Each restriction is either an
integer (to select a count of lines), or a decimal fraction between
0.0 and 1.0 inclusive (to select a percentage of lines), or a regular
expression (to pattern match the standard name that is printed). If
several restrictions are provided, then they are applied sequentially.
For example:
<P>
<UL COMPACT><CODE> print_stats(.1, "foo:")<P>
</CODE></UL>
would first limit the printing to first 10% of list, and then only
print functions that were part of filename `<SAMP>.*foo:</SAMP>'. In
contrast, the command:
<P>
<UL COMPACT><CODE> print_stats("foo:", .1)<P>
</CODE></UL>
would limit the list to all functions having file names `<SAMP>.*foo:</SAMP>',
and then proceed to only print the first 10% of them.
</DL>
<DL><DT><B>print_callers</B> (<VAR>restrictions</VAR>[, ...]) -- Method on Stats<DD>
This method for the <CODE>Stats</CODE> class prints a list of all functions
that called each function in the profiled database. The ordering is
identical to that provided by <CODE>print_stats()</CODE>, and the definition
of the restricting argument is also identical. For convenience, a
number is shown in parentheses after each caller to show how many
times this specific call was made. A second non-parenthesized number
is the cumulative time spent in the function at the right.
</DL>
<DL><DT><B>print_callees</B> (<VAR>restrictions</VAR>[, ...]) -- Method on Stats<DD>
This method for the <CODE>Stats</CODE> class prints a list of all function
that were called by the indicated function. Aside from this reversal
of direction of calls (re: called vs was called by), the arguments and
ordering are identical to the <CODE>print_callers()</CODE> method.
</DL>
<DL><DT><B>ignore</B> () -- Method on Stats<DD>
This method of the <CODE>Stats</CODE> class is used to dispose of the value
returned by earlier methods. All standard methods in this class
return the instance that is being processed, so that the commands can
be strung together. For example:
<P>
<UL COMPACT><CODE>pstats.Stats('foofile').strip_dirs().sort_stats('cum') \<P>
.print_stats().ignore()<P>
</CODE></UL>
would perform all the indicated functions, but it would not return
the final reference to the <CODE>Stats</CODE> instance.<A NAME="footnoteref1" HREF="#footnotetext1">(1)</A>
</DL>
<H2>---------- Footnotes ----------</H2>
<A NAME="footnotetext1" HREF="#footnoteref1">(1)</A>
This was once necessary, when Python would print any unused expression
result that was not <CODE>None</CODE>. The method is still defined for
backward compatibility.
<P>