使用Python性能优化技巧的总结

 from time import time 
 t = time() 
 list = ['a','b','is','python','jason','hello','hill','with','phone','test', 
'dfdf','apple','pddf','ind','basic','none','baecr','var','bana','dd','wrd'] 
 #list = dict.fromkeys(list,True) 
 print list 
 filter = [] 
 for i in range (1000000): 
	 for find in ['is','hat','new','list','old','.']: 
	 if find not in list: 
	 filter.append(find) 
 print "total run time:"
 print time()-t

 from time import time 
 t = time() 
 lista=[1,2,3,4,5,6,7,8,9,13,34,53,42,44] 
 listb=[2,4,6,9,23] 
 intersection=[] 
 for i in range (1000000): 
	 for a in lista: 
	 for b in listb: 
	 if a == b: 
	 intersection.append(a) 

 print "total run time:"
 print time()-t

 total run time: 
 38.4070000648

 from time import time 
 t = time() 
 lista=[1,2,3,4,5,6,7,8,9,13,34,53,42,44] 
 listb=[2,4,6,9,23] 
 intersection=[] 
 for i in range (1000000): 
	 list(set(lista)&set(listb)) 
 print "total run time:"
 print time()-t

 from time import time 
 t = time() 
 lista = [1,2,3,4,5,6,7,8,9,10] 
 listb =[0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,0.01] 
 for i in range (1000000): 
	 for a in range(len(lista)): 
	 for b in range(len(listb)): 
	 x=lista[a]+listb[b] 
 print "total run time:"
 print time()-t

 from time import time 
 t = time() 
 lista = [1,2,3,4,5,6,7,8,9,10] 
 listb =[0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,0.01] 
 len1=len(lista) 
 len2=len(listb) 
 for i in xrange (1000000): 
	 for a in xrange(len1): 
	 temp=lista[a] 
	 for b in xrange(len2): 
	 x=temp+listb[b] 
 print "total run time:"
 print time()-t

 from time import time 
 t = time() 
 abbreviations = ['cf.', 'e.g.', 'ex.', 'etc.', 'fig.', 'i.e.', 'Mr.', 'vs.'] 
 for i in range (1000000): 
	 for w in ('Mr.', 'Hat', 'is', 'chasing', 'the', 'black', 'cat', '.'): 
	 if w in abbreviations: 
	 #if w[-1] == '.' and w in abbreviations: 
	 pass 
 print "total run time:"
 print time()-t

 from time import time 
 t = time() 
 list = ['a','b','is','python','jason','hello','hill','with','phone','test', 
'dfdf','apple','pddf','ind','basic','none','baecr','var','bana','dd','wrd'] 
 total=[] 
 for i in range (1000000): 
	 for w in list: 
	 total.append(w) 
 print "total run time:"
 print time()-t

 for i in range (1000000): 
	 a = [w for w in list]

 import profile 
 def profileTest(): 
 Total =1; 
 for i in range(10): 
 Total=Total*(i+1) 
 print Total 
 return Total 
 if __name__ == "__main__": 
 profile.run("profileTest()")

 import pstats 
 p = pstats.Stats('testprof') 
 p.sort_stats("name").print_stats()

 C:Documents and SettingsAdministrator>pypy 
 Python 2.7.2 (0e28b379d8b3, Feb 09 2012, 18:31:47) 
 [PyPy 1.8.0 with MSC v.1500 32 bit] on win32 
 Type "help", "copyright", "credits" or "license" for more information. 
 And now for something completely different: ``PyPy is vast, and contains 
 multitudes''
 >>>>

 C:Documents and SettingsAdministrator 桌面 docpython>pypy loop.py 
 total run time: 
 8.42199993134 

 C:Documents and SettingsAdministrator 桌面 docpython>python loop.py 
 total run time: 
 106.391000032

 [root@v5254085f259 cpython]# wget -N http://cython.org/release/Cython-0.15.1.zip 
 --2012-04-16 22:08:35-- http://cython.org/release/Cython-0.15.1.zip 
 Resolving cython.org... 128.208.160.197 
 Connecting to cython.org|128.208.160.197|:80... connected. 
 HTTP request sent, awaiting response... 200 OK 
 Length: 2200299 (2.1M) [application/zip] 
 Saving to: `Cython-0.15.1.zip'

 100%[======================================>] 2,200,299 1.96M/s in 1.1s 

 2012-04-16 22:08:37 (1.96 MB/s) - `Cython-0.15.1.zip' saved [2200299/2200299]

 [root@v5254085f259 cpython]# unzip -o Cython-0.15.1.zip

 python setup.py install

 [root@v5254085f259 Cython-0.15.1]# cython 
 Cython (http://cython.org) is a compiler for code written in the 
 Cython language. Cython is based on Pyrex by Greg Ewing. 

 Usage: cython [options] sourcefile.{pyx,py} ... 

 Options: 
 -V, --version Display version number of cython compiler 
 -l, --create-listing Write error messages to a listing file 
 -I, --include-dir <directory> Search for include files in named directory 
 (multiple include directories are allowed). 
 -o, --output-file <filename> Specify name of generated C file 
 -t, --timestamps Only compile newer source files 
 -f, --force Compile all source files (overrides implied -t) 
 -q, --quiet Don't print module names in recursive mode 
 -v, --verbose Be verbose, print file names on multiple compil ation 
 -p, --embed-positions If specified, the positions in Cython files of each 
 function definition is embedded in its docstring. 
 --cleanup <level> 
 Release interned objects on python exit, for memory debugging. 
 Level indicates aggressiveness, default 0 releases nothing. 
 -w, --working <directory> 
 Sets the working directory for Cython (the directory modules are searched from) 
 --gdb Output debug information for cygdb 
 -D, --no-docstrings 
 Strip docstrings from the compiled module. 
 -a, --annotate 
 Produce a colorized HTML version of the source. 
 --line-directives 
 Produce #line directives pointing to the .pyx source 
 --cplus 
 Output a C++ rather than C file. 
 --embed[=<method_name>] 
 Generate a main() function that embeds the Python interpreter. 
 -2 Compile based on Python-2 syntax and code seman tics. 
 -3 Compile based on Python-3 syntax and code seman tics. 
 --fast-fail Abort the compilation on the first error 
 --warning-error, -Werror Make all warnings into errors 
 --warning-extra, -Wextra Enable extra warnings 
 -X, --directive <name>=<value> 
 [,<name=value,...] Overrides a compiler directive

 [root@v5254085f259 test]# python 
 ActivePython 2.7.2.5 (ActiveState Software Inc.) based on 
 Python 2.7.2 (default, Jun 24 2011, 11:24:26) 
 [GCC 4.0.2 20051125 (Red Hat 4.0.2-8)] on linux2 
 Type "help", "copyright", "credits" or "license" for more information. 
 >>> import pyximport; pyximport.install() 
 >>> import sum 
 >>> sum.sum(1,3)

 from time import time 
 def test(int n): 
 cdef int a =0 
 cdef int i 
 for i in xrange(n): 
 a+= i 
 return a 

 t = time() 
 test(10000000) 
 print "total run time:"
 print time()-t

 [GCC 4.0.2 20051125 (Red Hat 4.0.2-8)] on linux2 
 Type "help", "copyright", "credits" or "license" for more information. 
 >>> import pyximport; pyximport.install() 
 >>> import ctest 
 total run time: 
 0.00714015960693

 from time import time 
 def test(n): 
 a =0; 
 for i in xrange(n): 
 a+= i 
 return a 

 t = time() 
 test(10000000) 
 print "total run time:"
 print time()-t 

 [root@v5254085f259 test]# python test.py 
 total run time: 
 0.971596002579