Py vs Perl 运行

{{{俊杰蔡 <[email protected]> reply-to [email protected], to [email protected], date Thu, Apr 3, 2008 at 5:50 PM subject [CPyUG:45860] }}} [http://groups.google.com/group/python-cn/browse_thread/thread/4e4eb6d67a867c21/8b346859a4c96e29#8b346859a4c96e29 一段python程序的效率问题]

从以下对比得出

（a）random.random()函数比random.randrange()函数快。
（b）xrange不一定比range快。
（c）使用StringIO缓存全部内容，一下子写也不一定快。
（d）write() 块写效率会提高。
（e）print 到文件句柄写效率也不错高
（f）脚本越短，引用的模块越少效率好

time vs 0.1

attachment:vs-0.1.png

5" random.pl

use strict;


open (WW,"> 500000") or die "$!";
foreach(1..5000000){
my $i = int(rand 10000000) % 3;
print WW $i."\n";
}
close WW;

31" random.py

   1 import random
   2 import time
   3 
   4 __revision__ = '0.1'
   5 
   6 def test():
   7     fh = open("test_cjj","w")
   8    
   9     for i in range(5000000):
  10         data = random.randrange(1000000,9999999,1)
  11         yu = data % 3
  12         fh.write(str(yu)+"\n")
  13                                                   
  14     fh.close()
  15 
  16 if __name__ == "__main__" :
  17     test()

time vs 0.2

attachment:vs-0.2.png

48" random0.2.py

   1 import cStringIO as StringIO
   2 
   3 import random
   4 import time
   5 
   6 __revision__ = '0.2'
   7 
   8 def test():
   9     fh = open("test_cjj0.2","w")
  10     output = StringIO.StringIO()
  11   
  12     for i in xrange(5000000):
  13 
  14         data = random.randrange(1000000,9999999,1)
  15         yu = data % 3
  16         print >>output, yu                                          
  17    
  18     fh.write(output.getvalue())
  19 
  20     fh.close()
  21 
  22 if __name__ == "__main__" :
  23     test()

time vs 0.3

attachment:vs-0.3.png

33" random0.3.py

   1 import random
   2 import time
   3 
   4 __revision__ = '0.3'
   5 
   6 def test():    
   7     exp = ""
   8     for i in xrange(5000000):
   9         data = random.randrange(1000000,9999999,1)
  10         exp += "%s\n"%(str(data % 3))                             
  11    
  12     open("test_cjj0.3","w").write(exp)
  13 if __name__ == "__main__" :
  14     test()

time vs 0.4

attachment:vs-0.4.png

27" random0.4.py

   1 import random
   2 __revision__ = '0.4'
   3 
   4 fn = open("test_cjj0.4","w")
   5 for i in xrange(5000000):
   6     data = random.randrange(1000000,9999999,1)
   7     print >> fn, (data % 3)

time vs 0.5

attachment:vs-0.5.png

51" random0.5.py

   1 import cStringIO as StringIO
   2 import random
   3 __revision__ = '0.5'
   4 
   5 #fn = open("test_cjj0.4","w")
   6 out = StringIO.StringIO()
   7 for i in xrange(5000000):
   8     data = random.randrange(1000000,9999999,1)
   9     print >> out, (data % 3)
  10 
  11 open("test_cjj0.5","w").write(out.getvalue())

time vs 0.6

attachment:vs-0.6.png

26" random0.6.py

   1 import random
   2 __revision__ = '0.6'
   3 
   4 fn = open("test_cjj0.6","w")
   5 for i in xrange(5000000):
   6     print >> fn, (random.randrange(1000000,9999999,1))% 3

time vs 0.7

attachment:vs-0.7.png

10" random0.7.py

   1 from random import random
   2 __revision__ = '0.7'
   3 
   4 fh = open("test_cjj0.7","w")
   5 for i in range(5000000):
   6     print >> fh,(int(random()*(9999999-1000000)+1000000))% 3

time vs 0.8

attachment:vs-0.8.png

5" random0.8.py

   1 from random import random
   2 
   3 __revision__ = '0.8'
   4 
   5 def test():
   6     fh = open("test_cjj0.8","w")
   7     for i in range(5000000):
   8         print >> fh,(int(random()*(9999999-1000000)+1000000))% 3
   9 
  10 if __name__ == "__main__" : 
  11     try:
  12         import psyco
  13         psyco.full()
  14     except ImportError:
  15         pass
  16     test()

time vs 0.9

attachment:vs-0.9.png

15~11" random0.9.py

   1 from random import random
   2 __revision__ = '0.9'
   3 
   4 def test():
   5    five_million = 5000000
   6    fh = open("test_cjj0.9","w")
   7    for i in xrange(five_million):
   8        data = int(random()*(9999999))
   9        yu = data % 3
  10        fh.write('%d\n' % yu)
  11    fh.close()
  12 
  13 if __name__ == "__main__" :
  14     try:
  15         import psyco
  16         psyco.full()
  17     except ImportError:
  18         pass
  19     test()

time vs 1.0

attachment:vs-1.0.png

15~11" random1.0.py

   1 from random import random
   2 __revision__ = '0.9'
   3 
   4 def test():
   5    five_million = 5000000
   6    fh = open("test_cjj0.9","w")
   7    for i in xrange(five_million):
   8        data = int(random()*(9999999))
   9        yu = data % 3
  10        fh.write('%d\n' % yu)
  11    fh.close()
  12 
  13 if __name__ == "__main__" :
  14     try:
  15         import psyco
  16         psyco.full()
  17     except ImportError:
  18         pass
  19     test()

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创建 by -- ZoomQuiet [DateTime(2008-04-03T13:26:48Z)]

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