Python 字符串操作（string替换、删除、截取、复制、连接、比较、查找、包含、大小写转换、分割等）

去空格及特殊符号
s.strip().lstrip().rstrip(',')

复制字符串
#strcpy(sStr1,sStr)
sStr= 'strcpy'
sStr = sStr
sStr= 'strcpy'
print sStr

连接字符串
#strcat(sStr1,sStr)
sStr= 'strcat'
sStr = 'append'
sStr+= sStr
print sStr

查找字符
#strchr(sStr1,sStr)
sStr= 'strchr'
sStr = 's'
nPos = sStr1.index(sStr)
print nPos

比较字符串 : 0相等，-1不等
#str cmp(sStr1,sStr)
sStr= 'strchr'
sStr = 'strch'
print cmp(sStr1,sStr)

扫描字符串是否包含指定的字符
#strspn(sStr1,sStr)
sStr= '1345678'
sStr = '456'
#sStrand chars both in sStrand sStr
print len(sStrand sStr)

字符串长度
#strlen(sStr1)
sStr= 'strlen'
print len(sStr1)

将字符串中的大小写转换
#strlwr(sStr1)
sStr= 'JCstrlwr'
sStr= sStr1.upper()
#sStr= sStr1.lower()
print sStr

追加指定长度的字符串
#strncat(sStr1,sStr,n)
sStr= '1345'
sStr = 'abcdef'
n = 3
sStr+= sStr[0:n]
print sStr

字符串指定长度比较
#strncmp(sStr1,sStr,n)
sStr= '1345'
sStr = '13bc'
n = 3
print cmp(sStr1[0:n],sStr[0:n])

复制指定长度的字符
#strncpy(sStr1,sStr,n)
sStr= ''
sStr = '1345'
n = 3
sStr= sStr[0:n]
print sStr

将字符串前n个字符替换为指定的字符
#strnset(sStr1,ch,n)
sStr= '1345'
ch = 'r'
n = 3
sStr= n * ch + sStr1[3:]
print sStr

扫描字符串
#strpbrk(sStr1,sStr)
sStr= 'cekjgdklab'
sStr = 'gka'
nPos = -1
for c in sStr1:
if c in sStr:
nPos = sStr1.index(c)
break
print nPos

翻转字符串
#strrev(sStr1)
sStr= 'abcdefg'
sStr= sStr1[::-1]
print sStr

查找字符串
#strstr(sStr1,sStr)
sStr= 'abcdefg'
sStr = 'cde'
print sStr1.find(sStr)

分割字符串
#strtok(sStr1,sStr)
sStr= 'ab,cde,fgh,ijk'
sStr = ','
sStr= sStr1[sStr1.find(sStr) + 1:]
print sStr
或者
s = 'ab,cde,fgh,ijk'
print(s.split(','))

连接字符串
delimiter = ','
mylist = ['Brazil', 'Russia', 'India', 'China']
print delimiter.join(mylist)
PHP 中 addslashes 的实现
def addslashes(s):
d = {'"':'\\"', "'":"\\'", "\0":"\\\0", "\\":"\\\\"}
return ''.join(d.get(c, c) for c in s)
s = "John 'Johny' Doe (a.k.a. \"Super Joe\")\\\0"
print s
print addslashes(s)

只显示字母与数字
def OnlyCharNum(s,oth=''):
s = s.lower();
fomart = 'abcdefghijklmnopqrstuvwxyz013456789'
for c in s:
if not c in fomart:
s = s.replace(c,'');
return s;
print(OnlyStr("a000 aa-b"))

正则表达式，re模块

import re

常用函数：

1)compile()： //将正则表达式字符串编译成正则re对象

2)search() //在目标字符串中匹配正则表达式

3)match() //从目标字符串第一个字符开始匹配正则表达

search和match匹配成功返回MatchObject对象，失败返回None

>>> p = re.compile('abc')

>>> p.search('zabcy')

<_sre.SRE_Match object at 0x2a95659030>

不先编译成正则re对象也是可以的，上例也可以为：

>>> re.search('abc','xabcy')

<_sre.SRE_Match object at 0x2a95659098>

compile还可加些标志位，例如：re.I(re.IGNORECASE)忽略大小写

>>> p = re.compile('abc')

>>> print p.search('xAbCy')

None

>>> p = re.compile('abc',re.I)

>>> print p.search('xAbCy')

<_sre.SRE_Match object at 0x2a9565a098>

search和match区别见下例：

>>> p = re.compile('abc')

>>> print p.search('xxxabcyyy')
<_sre.SRE_Match object at 0x2a95659030>

>>> print p.match('xxxabcyyy')

None

>>> print p.match('abcyyy')

<_sre.SRE_Match object at 0x2a95659098>