Python stats: how do I write it to a (human readable) file

Question

I am using Python's hotshot profiler: http://docs.python.org/2/library/hotshot.html

It shows how to print the stats:

stats.print_stats(20)

But how do I get that into a file? I'm not sure how to get at the information so I can write it to a file using write().

EDIT:

I'd like the same easily readable result as is printed when it's done this way:

stats = hotshot.stats.load("stones.prof")
stats.strip_dirs()
stats.sort_stats('time', 'calls')
stats.print_stats(20) 

So it looks like this:

ncalls  tottime  percall  cumtime  percall filename:lineno(function)
     1    3.295    3.295   10.090   10.090 pystone.py:79(Proc0)

(So not for it to look like when I open stones.prof)

Answer 1

Stats takes an optional 'stream' argument. Simply open a file and pass the open file object to the Stats constructor as shown below. From that point any call to print_stats() will output to the stream you passed into the constructor. Hope this helps. :)

with open('path/to/output', 'w') as stream:
    stats = pstats.Stats('path/to/input', stream=stream)
    stats.print_stats()

Answer 2

How about output redirection?

import sys
import pstats
sys.stdout = open('readable.profile', 'w')
p = pstats.Stats('input.profile')
p.print_stats()

Answer 3

I ended up rewriting the print_stats() function, starting with copying it from pstats.py. It returns a string, which can then be written to a file. I have not tested every if-else loop, just that it works in the examples that I needed it for. I left the original lines commented out. I've left the variable names the same although it isn't really "self" that the function is using anymore.

stats = hotshot.stats.load("stones.prof")
stats.strip_dirs()
stats.sort_stats('time', 'calls')
readable_str = xprint_stats(stats, 20)

import pstats
def xprint_stats(self, *amount):
    x = ""
    for filename in self.files:
        x += " " + filename
    #if self.files: print >> self.stream
    # ?
    indent = ' ' * 8
    for func in self.top_level:
        #print >> self.stream, indent, xfunc_get_function_name(func)
        x += indent + pstats.func_get_function_name(func)

    #print >> self.stream, indent, self.total_calls, "function calls",
    x +=  indent + str(self.total_calls) + " function calls" + " "
    if self.total_calls != self.prim_calls:
        #print >> self.stream, "(%d primitive calls)" % self.prim_calls,
        x += "(%d primitive calls)" % self.prim_calls + " "
    #print >> self.stream, "in %.3f seconds" % self.total_tt
    #print >> self.stream
    x +=  "in %.3f seconds" % self.total_tt + "\n"
    #width, list = stats.get_print_list(amount)
    msg, width, list = xget_print_list(stats, amount)
    x += msg

    if list:
        #self.print_title()
        x += "\n" + '   ncalls  tottime  percall  cumtime  percall filename:lineno(function)'
        x += "\n"
        for func in list:
            #self.print_line(func)
            x +=  xprint_line(self, func) + "\n"
#        print >> self.stream
#        print >> self.stream
    #return self
    return x

def xprint_line(self, func):  
    x = ""
    cc, nc, tt, ct, callers = self.stats[func]
    c = str(nc)
    if nc != cc:
        c = c + '/' + str(cc)
#    print >> self.stream, c.rjust(9),
#    print >> self.stream, f8(tt),
    x +=  c.rjust(9) + " "
    x +=  pstats.f8(tt) + " "
    if nc == 0:
        #print >> self.stream, ' '*8,
       x +=  ' '*8 
    else:
        #print >> self.stream, f8(float(tt)/nc),
        x +=  pstats.f8(float(tt)/nc) + " "
    #print >> self.stream, f8(ct),
    x +=  pstats.f8(ct) + " "
    if cc == 0:
        #print >> self.stream, ' '*8,
        x +=  ' '*8
    else:
        #print >> self.stream, f8(float(ct)/cc),
        x +=   pstats.f8(float(ct)/cc) + " "
    #print >> self.stream, func_std_string(func)
    x +=  pstats.func_std_string(func) + " "
    return x

def xget_print_list(self, sel_list):
    width = self.max_name_len
    if self.fcn_list:
        stat_list = self.fcn_list[:]
        msg = "   Ordered by: " + self.sort_type + '\n'
    else:
        stat_list = self.stats.keys()
        msg = "   Random listing order was used\n"

    for selection in sel_list:
        stat_list, msg = self.eval_print_amount(selection, stat_list, msg)

    count = len(stat_list)

    if not stat_list:
        return 0, stat_list
    #print >> self.stream, msg
    if count < len(self.stats):
        width = 0
        for func in stat_list:
            if  len(pstats.func_std_string(func)) > width:
                width = len(pstats.func_std_string(func))
    #return width+2, stat_list
    return msg, width+2, stat_list