标签：
1.字符串的格式
1 learn_str = "ZiFuChuan" 2 learn_str = str("ZiFuChuan")
2.字符串的运行原理
1 learn_str = "ZiFuChuan" => "ZiFuChuan" = [‘Z‘,‘i‘,‘F‘,‘u‘...]
3.字符串的内置功能
*索引
1 learn_str = "ZiFuChuan" 2 print(learn_str[0]) => "Z" 3 print(learn_str[1]) => "i" 4 5 print(learn_str[-1]) => "n" 6 print(learn_str[-2]) => "a"
*切片
1 learn_str = "ZiFuChuan" 2 print(learn_str[0:3]) => "Zi" 3 print(learn_str[:3]) => "Zi" 4 5 print(learn_str[-3:0]) => 无返回 6 print(learn_str[-3:]) => ‘uan‘ 7 print(learn_str[-3:-1]) => "ua" 8 print(learn_str[:-1]) => "ZiFuChua"
* "+" 字符串连接
1 learn_str_1 = ‘wo‘ 2 learn_str_2 = ‘ni‘ 3 print(learn_str_1 + learn_str_2) => woni 4 print(‘wo‘ + ‘ni‘) => woni
* "*" 字符串的重复输出
1 learn_str_1 = ‘wo‘ 3 print(learn_str_1 * 3) => wowowo 4 print(‘wo‘ * 3) => wowowo
* capitalize() 第一个字母大写
1 learn_str = "ZiFuChuan" 2 print(learn_str.capitalize()) => Zifuchuan
* lower() 所有大写字母变为小写
1 learn_str = "ZiFuChuan" 2 print(learn_str.lower()) => zifuchuan
* upper() 所有小写字母变为大写
1 learn_str = "ZiFuChuan" 2 print(learn_str.upper()) => ZIFUCHUAN
* center(width,fillchar=None) 内容居中，空白处可填充
1 learn_str = "ZiFuChuan" 2 print(learn_str.center(20)) => " ZiFuChuan " 一共20位 3 print(learn_str.center(20,"*")) => "*****ZiFuChuan*****"
*ljust(width,fillchar=None) 内容左对齐，右侧填充
1 learn_str = "ZiFuChuan" 2 print(learn_str.ljust(20,‘*‘)) => ZiFuChuan**********
*rjust(width,fillchar=None) 内容右对齐，左侧填充
1 learn_str = "ZiFuChuan" 2 print(learn_str.rjust(20,‘*‘)) => **********ZiFuChuan
*count(sub,strat=None,end=None) 子序列个数
1 learn_str = "ZiFuChuan" 2 print(learn_str.count("u")) => 2 3 print(learn_str.count("u",4)) => 1 4 print(learn_str.count("u",4,6)) => 0
5 print(learn_str,count("hu")) => 1
*endswith(suffix,start=None,end=None) 是否以子序列结尾
learn_str = "ZiFuChuan" print(learn_str.endswith(‘n‘)) => True print(learn_str.endswith(‘an‘)) => True print(learn_str.endswith(‘i‘,0,2)) => True
* startswth(suffix,start=None,end=None) 是否以子序列开头
1 learn_str = "http://www.w3cschool.cc/" 2 print(learn_str.startswith(‘h‘)) ==》 Thue
*expandtabs(tablesize=None) 将tab转换为空格，默装换为8个空格
learn_str = "ZiFu\tChuan" print(learn_str.expandtabs()) => "ZiFu Chuan" print(learn_str.expandtabs(2)) => "ZiFu Chuan"
*find(sub,start=None,end=None) 寻找子序列位置，若未找到返回-1
learn_str = "ZiFuChuan" print(learn_str.find("u")) => 3 print(learn_str.find(‘iF‘)) => 1 print(learn_str.find(‘g‘)) => -1 print(learn_str.find(‘F‘, 1, 3)) => 2 此处区间位置不会按照所在位置取 print(learn_str.find(‘F‘, 3, 4)) => -1
*rfind(sub,start=None,end=None) 寻找子序列位置，从右边开始，若未找到返回-1
1 learn_str = "ZiFuChuan" 2 print(learn_str.find("u")) => 6
*index(sub,start=None,end=None) 寻找子序列位置，若未找到报错
1 learn_str = "ZiFuChuan" 2 print(learn_str.index(‘u‘)) => 3 3 print(learn_str.index(‘W‘)) => 报错
*rindex(sub,start=None,end=None) 寻找子序列位置，从右边开始，若未找到报错
1 learn_str = "ZiFuChuan" 2 print(learn_str.rindex(‘u‘)) => 6 3 print(learn_str.rindex(‘W‘)) => 报错
*format() 字符串的格式化
print(‘My {} is {}‘.format(‘haha‘,‘hehe‘)) => My haha is hehe print(‘My {name} is {names}‘.format(name=‘haha‘,names=‘hehe‘)) => My haha is hehe
*join(iterable) 连接
1 learn_str = (‘a‘,‘b‘,‘c‘,‘d‘,‘e‘) 2 print(‘‘.join(learn_str)) => abcde 3 print(‘-‘.join(learn_str)) => a-b-c-d-e
*strip(chars=None) 移除字符串两侧空白或指定序列
1 learn_str = " ZiFuChuan " 2 print(learn_str.strip()) => ZiFuChuan 3 learn_str = "**ZiFuChuan**" 4 print(learn_str.srtip(‘*‘)) => ZiFuChuan
*lstrip(chars=None) 移除字符串左侧空白或指定序列
learn_str = " ZiFuChuan " print(learn_str.lstrip()) => ‘ZiFuChuan ‘ learn_str = "**ZiFuChuan**" print(learn_str.lstrip(‘*‘)) => "ZiFuChuan**"
*rstrip(chars=None) 移除字符串右侧空白或指定序列
1 learn_str = " ZiFuChuan " 2 print(learn_str.rstrip()) => ‘ ZiFuChuan‘ 3 learn_str = "**ZiFuChuan**" 4 print(learn_str.rstrip(‘*‘)) => "**ZiFuChuan"
*partition(sep) 分割前中后三个部分
1 str = "http://www.w3cschool.cc/" 2 print(str.partition(‘://‘)) 3 ==> [‘http‘ ‘://‘ ‘www.w3cschool.cc/‘]
*rpartition(sep) 分割前中后三个部分，从右侧检测
1 learn_str = "http://www.w3cschool.cc/" 2 print(learn_str.rpartition(‘w‘)) 3 ==> [‘http://www.‘ ‘w‘ ‘3cschool.cc/‘]
*split(str="",num=srting.count(str)) 通过指定分隔符对字符串进行切片，如果参数num 有指定值，则仅分隔 num 个子字符串
1 learn_str = "http://www.w3cschool.cc/" 2 print(learn_str.split("w")) 3 ==> [‘http://‘, ‘‘, ‘‘, ‘.‘, ‘‘, ‘3cschool.cc/‘] 4 print(learn_str.split("w",2)) 5 ==> [‘http://‘, ‘‘, ‘w.w3cschool.cc/‘]
*rsplit(str="",num=srting.count(str)) 从右侧开始检索，通过指定分隔符对字符串进行切片，如果参数num 有指定值，则仅分隔 num 个子字符串
learn_str = "http://www.w3cschool.cc/" print(learn_str.rsplit("w")) ==》 [‘http://‘, ‘‘, ‘‘, ‘.‘, ‘3cschool.cc/‘] print(learn_str.rsplit("w",2)) ==》 [‘http://ww‘, ‘.‘, ‘3cschool.cc/‘]
* replace(old,new,count=None) 替换字符列
1 learn_str = "ZiFuChuan" 2 print(learn_str.replace(‘u‘,‘s‘)) => ZiFsChsan 3 print(learn_str.replace(‘Fu‘,‘s‘)) => ZisChuan 4 print(learn_str.replace(‘u‘,‘s‘,1)) => ZiFsChuan 5 ==>count参数表示替换的个数
* translate(table,deletechars=None) 转换，需要先做一个对应表。
1 intab = ‘aeiou‘ 2 outtab = ‘12345‘ 3 trantab = str.maketrans(intab, outtab) 4 5 learn_str = ‘this is string example...wow!!!‘ 6 print(learn_str.translate(trantab)) 7 ==》th3s 3s str3ng 2x1mpl2...w4w!!!
* zfill 返回指定长度的字符串，原字符串右对齐，前面填充0。
1 learn_str = "ZiFuChuan" 2 print(learn_str.zfill(15)) => "000000ZiFuChuan"
* decode() 解码
* encode() 编码针对unicode
* isalnum() 是否是字母和数字，返回布尔值
* isalpha() 是否是字母，返回布尔值
* isalgif() 是否是字母，返回布尔值
* islower() 是否小写，返回布尔值
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原文地址：http://www.cnblogs.com/guantouping/p/5839433.html
