1.3 python迭代工具最小計時

描述

timertool.py：

timer_compatible()：根據(jù)win版、Unix版、python版本選擇對應(yīng)計時函數(shù)計算總時間。

mintime()：計算每個迭代工具執(zhí)行的最小時間。

timeiterevn.py：

timeiter_compatible()：計算每個迭代工具執(zhí)行的總時間、平均時間、最小時間。

示例

#timertool.py
import time,sys
reps = 1000
repslist = range(reps)

if sys.version[:3]<'3.3':
   if sys.platform[:3] == 'win':
       timefunc = time.clock
   else:
       timefunc = time.time
else:
   timefunc = time.perf_counter
   
def trace(*args):
   #print('args={}'.format(args))
   pass

def timer(func,*pargs,**kargs):
   begin = time.perf_counter()
   for i in repslist:
       ret = func(*pargs,**kargs)
   usetime = time.perf_counter() - begin
   return (usetime,ret)

def timer_compatible(func,*pargs,**kargs):
   _reps = kargs.pop('_reps',1000)
   trace(func,pargs,kargs,_reps)
   repslist = range(_reps)
   begin = timefunc()
   for i in repslist:
       ret = func(*pargs,**kargs)
   usetime = timefunc() - begin
   return (usetime,ret)
   
def mintime(func,*pargs,**kargs):
   _reps = kargs.pop('_reps',50)
   mintime = 2 ** 32
   for i in range(_reps):
      (usetime,ret) = timer_compatible(func,*pargs,_reps=1,**kargs)
       if usetime < mintime:
           mintime = usetime
   return (mintime,ret)
   
# timeiterevn.py
import sys,timertool
s = '梯閱線條tyxt'*1000

def forloop():
   res = []
   for x in s:
       res.append(ord(x)+1)
   return res
   
def listComp():
   return [ord(x) for x in s]

def mapCall():
   return list(map(lambda x:ord(x)+1,s))
   
def genExpr():
   return list(ord(x)+1 for x in s)
   
def genFunc():
   def gen():
       for x in s:
           yield ord(x)+1
   return list(gen())
def commstr(s):
   commstr = '# '+s
   print(commstr)
functp = (forloop,listComp,mapCall,genExpr,genFunc)
timetp = (timertool.timer_compatible,timertool.mintime)
commstr('-'*33)
commstr(str(sys.version))
def timeiter():
   reslist=[]
   for test in funcList:
       usetime,result = timertool.timer(test)
       reslist.append((test.__name__,usetime,result[0],result[-1],len(result)))

   commstr('-'*33)        
   reslistsort=sorted(reslist,key = lambda x:x[1])
   for L in reslistsort:
       #print(commstr+'%-9s:%.5f=>[%s....%s....%s]'%(L[0],L[1],L[2],L[3],L[4]))
       commstr('%-9s:%.5f=>[%s....%s....%s]'%(L[0],L[1],L[2],L[3],L[4]))
   commstr('-'*33)  

def timeiter_compatible():
   _reps = 1000
   commstr('-'*33)
   for ttp in timetp:
       reslist=[]
       commstr('<{}>'.format(ttp.__name__))
       for ftp in functp:
           usetime,result = ttp(ftp,_reps=_reps)
           reslist.append((ftp.__name__,usetime,result[0],result[-1],len(result)))
       commstr('-'*33)
       reslistsort=sorted(reslist,key = lambda x:x[1])
       if ttp.__name__ == 'timer_compatible':
           commstr('總時間排序')
       else:
           commstr('最小時間排序')
       commstr('-'*33)
       for L in reslistsort:
           commstr('%-9s:%.5f=>[%s....%s....%s]'%(L[0],L[1],L[2],L[3],L[4]))
       commstr('-'*33)
       if ttp.__name__ == 'timer_compatible':
           commstr('平均時間排序')
           commstr('-'*33)
           for L in reslistsort:
               commstr('%-9s:%.5f=>[%s....%s....%s]'%(L[0],(L[1]/_reps),L[2],L[3],L[4]))
           commstr('-'*33)
timeiter_compatible()

# ---------------------------------
# 3.7.8 (tags/v3.7.8:4b47a5b6ba, Jun 28 2020, 07:55:33) [MSC v.1916 32 bit (Intel)]
# ---------------------------------
# 
# ---------------------------------
# 總時間排序
# ---------------------------------
# listComp :0.52310=>[26799....116....8000]
# genFunc :0.92414=>[26800....117....8000]
# genExpr :0.94791=>[26800....117....8000]
# forloop :1.01522=>[26800....117....8000]
# mapCall :1.12953=>[26800....117....8000]
# ---------------------------------
# 平均時間排序
# ---------------------------------
# listComp :0.00052=>[26799....116....8000]
# genFunc :0.00092=>[26800....117....8000]
# genExpr :0.00095=>[26800....117....8000]
# forloop :0.00102=>[26800....117....8000]
# mapCall :0.00113=>[26800....117....8000]
# ---------------------------------
# 
# ---------------------------------
# 最小時間排序
# ---------------------------------
# listComp :0.00039=>[26799....116....8000]
# genFunc :0.00065=>[26800....117....8000]
# genExpr :0.00066=>[26800....117....8000]
# forloop :0.00072=>[26800....117....8000]
# mapCall :0.00073=>[26800....117....8000]
# ---------------------------------

1.4 time計時

描述

python的time模塊對Windows、Unix、python版本提供不同計時方法。

兩次調(diào)用之間的時間差用于計時。

示例

>>> import time
>>> begin = time.clock()
>>> end = time.clock()
>>> use=end - begin
>>> begin,end,use
(782.9449924, 793.3414938, 10.39650139999992)
>>> begin = time.time()
>>> end = time.time()
>>> use = end - begin
>>> begin,end,use
(1674368678.73148, 1674368685.6409733, 6.909493446350098)
>>> begin = time.perf_counter()
>>> end = time.perf_counter()
>>> use = end - begin
>>> begin,end,use
(899.3102242, 908.7626699, 9.452445699999998)

1.5 sys平臺版本

描述

python通過sys模塊獲取平臺版本信息。

示例

>>> import sys
>>> v=sys.version
>>> pf=sys.platform
>>> v
'3.7.8 (tags/v3.7.8:4b47a5b6ba, Jun 28 2020, 07:55:33) [MSC v.1916 32 bit (Intel)]'
>>> pf
'win32'
>>> v[:3],pf[:3]
('3.7', 'win')

1.6 sorted按鍵排序

用法

sorted(iterable, /, *, key=None, reverse=False)

描述

python內(nèi)置函數(shù)sorted(可迭代對象,key)屬于迭代工具，按指定key對可迭代對象進行排序。

key：自定義排序函數(shù)。

reverse：默認False為升序。

示例

>>> zs={'name':'張三','yuwen':90,'shuxue':100,'english':60}
>>> ls={'name':'李四','yuwen':91,'shuxue':95,'english':85}
>>> ww={'name':'王五','yuwen':80,'shuxue':99,'english':82}
>>> classOne=[zs,ls,ww]
>>> for i,stu in zip(range(1,len(classOneSort)+1),classOneSort):
   zf = stu['yuwen']+stu['shuxue']+stu['english']
   print("總分第{i:0>3}名:{d[name]:>4},語文={d[yuwen]:>3},數(shù)學(xué)={d[shuxue]:>3},英語={d[english]:>3},總分={zf:>3}".format(d=stu,zf=zf,i=i))

   
總分第001名:  李四,語文= 91,數(shù)學(xué)= 95,英語= 85,總分=271
總分第002名:  王五,語文= 80,數(shù)學(xué)= 99,英語= 82,總分=261
總分第003名:  張三,語文= 90,數(shù)學(xué)=100,英語= 60,總分=250