基准测试python脚本揭示了神秘的时间延迟

Question

我有两个模块：moduleParent和moduleChild

我在moduleParent中做了这样的事情：

import moduleChild

#a bunch of code

start = time.time()
moduleChild.childFunction()
finish = time.time()
print "calling child function takes:", finish-start, "total seconds"

#a bunch of code

我在moduleChild中做了这样的事情：

^{pr2}$

输出如下：

calling child function takes: .24 total seconds
child function says it takes: 0.0 total seconds

所以我的问题是，这些。额外的24秒从哪里来？在

谢谢你的专业知识。在

#

这是“儿童游戏”的实际代码。真的不需要。24秒。在

 def getResources(show, resourceName='', resourceType=''):
   '''
   get a list of resources with the given name

   @show: show name
   @resourceName: name of resource
   @resourceType: type of resource
   @return: list of resource dictionaries
   '''

   t1 = time.time()

   cmd = r'C:\tester.exe -cmdFile "C:\%s\info.txt" -user root -pwd root'%show
   cmd += " -cmd findResources -machineFormatted "

   if resourceName:
       cmd += '-name %s'%resourceName

   if resourceType:
       cmd += '_' + resourceType.replace(".", "_") + "_"

   proc=subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
   output = proc.stdout.read()
   output = output.strip()

   resourceData = output.split("\r\n")
   resourceData = resourceData[1:]

   resourceList = []
   for data in resourceData:
       resourceId, resourceName, resourceType = data.split("|")
       rTyp = "_" + resourceType.replace(".", "_") + "_"
       shot, assetName = resourceName.split(rTyp)
       resourceName = assetName
       path = '//projects/%s/scenes/%s/%s/%s'%(show, shot, resourceType.replace(".", "/"), assetName)
       resourceDict = {'id':resourceId, 'name':resourceName, 'type':resourceType, 'path':path }
       resourceList.append(resourceDict)

   t2 = time.time()
   print ("     ", t2 - t2, "seconds")


   return resourceList

Answer 1

你不能通过运行一次来度量函数的时间，尤其是运行时间很短的函数。有很多因素可能会影响计时，其中最重要的是您在系统上运行的其他进程。在

像这样的事情我可能至少跑几百次。查看timeit模块。在