Python str方法总结
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1．返回第一个字母大写
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>>>a = ‘shaw‘>>> b = a.capitalize()>>> print bShaw |
2．按指定长度填充特定字符
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>>> a = ‘linux‘>>> print a.center(7,‘h‘)hlinuxh>>> print a.center(8,‘h‘)hlinuxhh>>> print a.center(9,‘h‘)hhlinuxhh |
3．查找某字符串出现的次数
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>>> a = "this is my dog, i love this dog and it‘s a good dog!">>> print a.count(‘dog‘)3>>> print a.count(‘dog‘,15)2>>> print a.count(‘dog‘,15,30)0>>> print a.count(‘dog‘,15,32)1 |
4.以指定的编码格式解码字符串。默认编码为字符串编码（适合python2中处理中文）
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b = ‘strid‘>>> b.decode(‘utf-8‘)u‘strid‘ |
5.用于判断字符串是否以指定后缀结尾，如果以指定后缀结尾返回True，否则返回False。可选参数"start"与"end"为检索字符串的开始与结束位置
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>>> shaw = ‘I am shaw,what\‘s your name ?‘>>> shaw.endswith(‘?‘)True>>> shaw.endswith(‘w‘,7,9)True>>> shaw.endswith(‘w‘,7,8)False |
6.把字符串中的 tab 符号(‘\t‘)转为空格，tab 符号(‘\t‘)默认的空格数是8，tabsize -- 指定转换字符串中的 tab 符号(‘\t‘)转为空格的字符数。
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>>> info = ‘today is a good d\tay‘>>> print info.expandtabs()today is a good d ay>>> print info.expandtabs(4) # 把tab装换成4个空格today is a good d ay >>> printinfo.expandtabs(1)today is a good d ay # 把tab装换成1个空格 |
7.检测字符串中是否包含子字符串 str ，如果指定 beg（开始）和 end（结束）范围，则检查是否包含在指定范围内，如果包含子字符串，则返回开始的索引值，否则返回-1。
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>>> a = ‘stivenwang‘>>> a.find(‘w‘)6>>> a.find(‘w‘,9)-1>>> a.find(‘w‘,9,11)-1 |
8．格式换字符串输出（方法与%相似，但可以指定顺序）
margin-bottom: 0px;">9.检测字符串string中是否包含子字符串 str ，如果存在，则返回str在string中的索引值，如果指定beg（开始）和 end（结束）范围，则检查是否包含在指定范围内，该方法与 python find()方法一样，只不过如果str不在 string中会报一个异常(ValueError: substring not found)。 index(...) S.index(sub [,start [,end]])-> int
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>>> name = ‘StivenWang‘>>> fruit = ‘apple‘>>> print ‘my name is {},I like {}‘.format(name,fruit)my name is StivenWang,I like apple>>> print ‘my name is {1},I like {0}‘.format(fruit,name)my name is StivenWang,I like apple>>> print ‘my name is {mingzi},I like{shuiguo}‘.format(shuiguo=fruit,mingzi=name)my name is StivenWang,I like apple |
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>>> str1 = "this is string example....wow!!!">>> str2 = "exam">>> print str1.index(str2)15>>> print str1.index(str2,20)Traceback (most recent call last): File "<input>",line 1, in <module>ValueError: substringnot found报错 |
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>>> a = ‘123‘>>> a.isalnum()True>>> b = ‘shaw‘>>> b.isalnum()True>>> c = ‘shaw123‘>>> c.isalnum()True>>> d = ‘th 123‘>>> d.isalnum()False |
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>> a = ‘123‘>>> a.isalpha()False>>> b = ‘123shaw‘>>> b.isalpha()False>>> c = ‘shaw‘>>> c.isalpha()True>>> d = ‘sha w‘>>> d.isalpha()False |
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>>> a = ‘123‘>>> a.isdigit()True>>> b = ‘shaw‘>>> b.isdigit()False>>> c = ‘123shaw‘>>> c.isdigit()False |
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>>> a = ‘shaw‘>>> a.islower()True>>> b = ‘123‘>>> a.islower()True>>> c = ‘123shaw‘>>> c.islower()True>>> d = ‘SHAW‘>>> d.islower()False>>> e = ‘123SHAW‘>>> e.islower()False |
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>>> a = ‘ ‘>>> a.isspace()True>>> a = ‘123‘>>> a.isspace()False>>> a = ‘shaw‘>>> a.isspace()False |
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>>> a = ‘Shaw‘>>> a.istitle()True>>> a = ‘Shaw123‘>>> a.istitle()True>>> a = ‘123‘>>> a.istitle()False |
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>>> a = ‘123‘>>> a.isupper()False>>> a = ‘Shaw‘>>> a.isupper()False>>> a = ‘Shaw123‘>>> a.isupper()False>>> a = ‘SHAW123‘>>> a.isupper()True |
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>>> a = ‘-‘>>> b = ‘shaw‘>>> print a.join(b)s-h-a-w |
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>>> s = ‘shaw‘>>> s.ljust(10)‘shaw ‘>>> s.ljust(10,‘8‘)‘shaw888888‘ |
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>>> s = ‘PYTHON‘>>> s.lower()‘python‘>>> s = ‘PYTHON123‘>>> s.lower()‘python123‘ |
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>>> s = ‘%%%shaw‘>>> s.lstrip(‘%‘)‘shaw‘>>> s = ‘ shaw‘>>> s.lstrip()‘shaw‘ |
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>>> S = ‘are you know:lilin is lowser‘>>> S.partition(‘lilin‘)(‘are you know:‘, ‘lilin‘, ‘ is lowser‘) |
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>>> S = ‘shaw‘>>> S.replace(‘sh‘,‘LI‘)‘LIaw‘ |