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Remove unused imports in IPython.kernel
Remove unused imports in IPython.kernel

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timing.py
116 lines | 4.0 KiB | text/x-python | PythonLexer
# encoding: utf-8
"""
Utilities for timing code execution.
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2008-2011 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
import time
#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------
# If possible (Unix), use the resource module instead of time.clock()
try:
import resource
def clocku():
"""clocku() -> floating point number
Return the *USER* CPU time in seconds since the start of the process.
This is done via a call to resource.getrusage, so it avoids the
wraparound problems in time.clock()."""
return resource.getrusage(resource.RUSAGE_SELF)[0]
def clocks():
"""clocks() -> floating point number
Return the *SYSTEM* CPU time in seconds since the start of the process.
This is done via a call to resource.getrusage, so it avoids the
wraparound problems in time.clock()."""
return resource.getrusage(resource.RUSAGE_SELF)[1]
def clock():
"""clock() -> floating point number
Return the *TOTAL USER+SYSTEM* CPU time in seconds since the start of
the process. This is done via a call to resource.getrusage, so it
avoids the wraparound problems in time.clock()."""
u,s = resource.getrusage(resource.RUSAGE_SELF)[:2]
return u+s
def clock2():
"""clock2() -> (t_user,t_system)
Similar to clock(), but return a tuple of user/system times."""
return resource.getrusage(resource.RUSAGE_SELF)[:2]
except ImportError:
# There is no distinction of user/system time under windows, so we just use
# time.clock() for everything...
clocku = clocks = clock = time.clock
def clock2():
"""Under windows, system CPU time can't be measured.
This just returns clock() and zero."""
return time.clock(),0.0
def timings_out(reps,func,*args,**kw):
"""timings_out(reps,func,*args,**kw) -> (t_total,t_per_call,output)
Execute a function reps times, return a tuple with the elapsed total
CPU time in seconds, the time per call and the function's output.
Under Unix, the return value is the sum of user+system time consumed by
the process, computed via the resource module. This prevents problems
related to the wraparound effect which the time.clock() function has.
Under Windows the return value is in wall clock seconds. See the
documentation for the time module for more details."""
reps = int(reps)
assert reps >=1, 'reps must be >= 1'
if reps==1:
start = clock()
out = func(*args,**kw)
tot_time = clock()-start
else:
rng = xrange(reps-1) # the last time is executed separately to store output
start = clock()
for dummy in rng: func(*args,**kw)
out = func(*args,**kw) # one last time
tot_time = clock()-start
av_time = tot_time / reps
return tot_time,av_time,out
def timings(reps,func,*args,**kw):
"""timings(reps,func,*args,**kw) -> (t_total,t_per_call)
Execute a function reps times, return a tuple with the elapsed total CPU
time in seconds and the time per call. These are just the first two values
in timings_out()."""
return timings_out(reps,func,*args,**kw)[0:2]
def timing(func,*args,**kw):
"""timing(func,*args,**kw) -> t_total
Execute a function once, return the elapsed total CPU time in
seconds. This is just the first value in timings_out()."""
return timings_out(1,func,*args,**kw)[0]