我正在研究Python中的字符串方法,以便使用最快的方法。 我有这段代码来测试文件中的字符串拼接、StringIO、BytesIO和正常字符串。
#!/usr/bin/env python
#title : pythonTiming.py
#description : Will be used to test timing function in python
#author : myusuf
#date : 19-11-2014
#version : 0
#usage :python pythonTiming.py
#notes :
#python_version :2.6.6
#==============================================================================
import time
import cStringIO
import StringIO
class Timer(object):
def __enter__(self):
self.start = time.time()
return self
def __exit__(self, *args):
self.end = time.time()
self.interval = self.end - self.start
testbuf = """ Hello This is a General String that will be repreated
This string will be written to a file , StringIO and a sregualr strin then see the best to handle string according to time
""" * 1000
MyFile = open("./testfile.txt" ,"wb+")
MyStr = ''
MyStrIo = StringIO.StringIO()
MycStrIo = cStringIO.StringIO()
def strWithFiles():
global MyFile
print "writing string to file "
for index in range(1000):
MyFile.write(testbuf)
pass
def strWithStringIO():
global MyStrIo
print "writing string to StrinIO "
for index in range(1000):
MyStrIo.write(testbuf)
def strWithStr():
global MyStr
print "Writing String to STR "
for index in range(500):
MyStr = MyStr + testbuf
def strWithCstr():
global MycStrIo
print "writing String to Cstring"
for index in range(1000):
MycStrIo.write(testbuf)
with Timer() as t:
strWithFiles()
print('##Request took %.03f sec.' % t.interval)
with Timer() as t:
strWithStringIO()
print('###Request took %.03f sec.' % t.interval)
with Timer() as t:
strWithCstr()
print('####Request took %.03f sec.' % t.interval)
with Timer() as t:
read1 = 'x' + MyFile.read(-1)
print('file read ##Request took %.03f sec.' % t.interval)
with Timer() as t:
read2 = 'x' + MyStrIo.read(-1)
print('stringIo read ###Request took %.03f sec.' % t.interval)
with Timer() as t:
read3 = 'x' + MycStrIo.read(-1)
print('CString read ####Request took %.03f sec.' % t.interval)
MyFile.close()
Python文档网站称
cStringIO
比StringIO
更快,但实际测试结果表明在字符串连接方面StringIO
表现更好。为什么?另一方面,从
cStringIO
中读取数据比从StringIO
中读取数据要快(与文件类似),因为我看到文件和cStringIO
的实现都是用C语言编写的,那么为什么字符串连接速度较慢呢?除了这些方法之外,还有没有其他更快的处理字符串的方式?
cStringIO
模块中的C代码。请参见PEP-8的Programming Recommendations部分中的第一个要点。 - martineau