【python之路7】python基本数据类型（一）int bool string
一、运算符
1、算数运算符
+、-、*、/、%（求余数）、//（取整数部分）
python2.x中，如果计算浮点数其中一个数字必须是浮点数否则按整数计算：
如python2.7中：print 9/2 结果是4
python2.7中：print 9.0/2 结果是4.5
python3.0中：print 9/2 结果是4.5
那么怎么在python2.7中让9/2输出4.5呢？可以通过下面的代码实现：
from __future__ import division print 9/2
2、 比较运算符
==、!=或<>、>、<、>=、<=
3、赋值运算符
=、+=、-=、*=、/=、%=、**=、//=
4、逻辑运算符
and、or、not
5、成员运算符
in、not in
二、基本数据类型
#!/usr/bin/env python # -*- coding:utf-8 -*- i = 1 print(type(i)) #查看属于哪个类 print(dir(i)) #查看有哪些方法 help(i) #类及方法的详细介绍
1、int(数字)
在32位机器上，整数的位数为32位，取值范围为-2**31～2**31-1，即-2147483648～2147483647
在64位系统上，整数的位数为64位，取值范围为-2**63～2**63-1，即-9223372036854775808～9223372036854775807
class int(object):
"""
int(x=0) -> int or long
int(x, base=10) -> int or long
Convert a number or string to an integer, or return 0 if no arguments
are given. If x is floating point, the conversion truncates towards zero.
If x is outside the integer range, the function returns a long instead.
If x is not a number or if base is given, then x must be a string or
Unicode object representing an integer literal in the given base. The
literal can be preceded by '+' or '-' and be surrounded by whitespace.
The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to
interpret the base from the string as an integer literal.
>>> int('0b100', base=0)
"""
def bit_length(self):
""" 返回表示该数字的时占用的最少位数 """
"""
int.bit_length() -> int
Number of bits necessary to represent self in binary.
"""用二进制必须的比特数来表示self参数"""
>>> bin(37)
'0b100101'
>>> (37).bit_length()
"""
return 0
def conjugate(self, *args, **kwargs): # real signature unknown
""" 返回该复数的共轭复数 """
""" Returns self, the complex conjugate of any int. """
pass
def __abs__(self):
""" 返回绝对值 """
""" x.__abs__() <==> abs(x) """
pass
def __add__(self, y):
""" x.__add__(y) <==> x+y """
pass
def __and__(self, y):
""" x.__and__(y) <==> x&y """
pass
def __cmp__(self, y):
""" 比较两个数大小 """
""" x.__cmp__(y) <==> cmp(x,y) """
pass
def __coerce__(self, y):
""" 强制生成一个元组 """
""" x.__coerce__(y) <==> coerce(x, y) """
pass
def __divmod__(self, y):
""" 相除，得到商和余数组成的元组 """
""" x.__divmod__(y) <==> divmod(x, y) """
pass
def __div__(self, y):
""" x.__div__(y) <==> x/y """
pass
def __float__(self):
""" 转换为浮点类型 """
""" x.__float__() <==> float(x) """
pass
def __floordiv__(self, y):
""" x.__floordiv__(y) <==> x//y """
pass
def __format__(self, *args, **kwargs): # real signature unknown
pass
def __getattribute__(self, name):
""" x.__getattribute__('name') <==> x.name """
pass
def __getnewargs__(self, *args, **kwargs): # real signature unknown
""" 内部调用 __new__方法或创建对象时传入参数使用 """
pass
def __hash__(self):
"""如果对象object为哈希表类型，返回对象object的哈希值。哈希值为整数。在字典查找中，哈希值用于快速比较字典的键。两个数值如果相等，则哈希值也相等。"""
""" x.__hash__() <==> hash(x) """
pass
def __hex__(self):
""" 返回当前数的 十六进制 表示 """
""" x.__hex__() <==> hex(x) """
pass
def __index__(self):
""" 用于切片，数字无意义 """
""" x[y:z] <==> x[y.__index__():z.__index__()] """
pass
def __init__(self, x, base=10): # known special case of int.__init__
""" 构造方法，执行 x = 123 或 x = int(10) 时，自动调用，暂时忽略 """
"""
int(x=0) -> int or long
int(x, base=10) -> int or long
Convert a number or string to an integer, or return 0 if no arguments
are given. If x is floating point, the conversion truncates towards zero.
If x is outside the integer range, the function returns a long instead.
If x is not a number or if base is given, then x must be a string or
Unicode object representing an integer literal in the given base. The
literal can be preceded by '+' or '-' and be surrounded by whitespace.
The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to
interpret the base from the string as an integer literal.
>>> int('0b100', base=0)
# (copied from class doc)
"""
pass
def __int__(self):
""" 转换为整数 """
""" x.__int__() <==> int(x) """
pass
def __invert__(self):
""" x.__invert__() <==> ~x """
pass
def __long__(self):
""" 转换为长整数 """
""" x.__long__() <==> long(x) """
pass
def __lshift__(self, y):
""" x.__lshift__(y) <==> x<<y """
pass
def __mod__(self, y):
""" x.__mod__(y) <==> x%y """
pass
def __mul__(self, y):
""" x.__mul__(y) <==> x*y """
pass
def __neg__(self):
""" x.__neg__() <==> -x """
pass
@staticmethod # known case of __new__
def __new__(S, *more):
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass
def __nonzero__(self):
""" x.__nonzero__() <==> x != 0 """
pass
def __oct__(self):
""" 返回改值的 八进制 表示 """
""" x.__oct__() <==> oct(x) """
pass
def __or__(self, y):
""" x.__or__(y) <==> x|y """
pass
def __pos__(self):
""" x.__pos__() <==> +x """
pass
def __pow__(self, y, z=None):
""" 幂，次方 """
""" x.__pow__(y[, z]) <==> pow(x, y[, z]) """
pass
def __radd__(self, y):
""" x.__radd__(y) <==> y+x """
pass
def __rand__(self, y):
""" x.__rand__(y) <==> y&x """
pass
def __rdivmod__(self, y):
""" x.__rdivmod__(y) <==> divmod(y, x) """
pass
def __rdiv__(self, y):
""" x.__rdiv__(y) <==> y/x """
pass
def __repr__(self):
"""转化为解释器可读取的形式 """
""" x.__repr__() <==> repr(x) """
pass
def __str__(self):
"""转换为人阅读的形式，如果没有适于人阅读的解释形式的话，则返回解释器课阅读的形式"""
""" x.__str__() <==> str(x) """
pass
def __rfloordiv__(self, y):
""" x.__rfloordiv__(y) <==> y//x """
pass
def __rlshift__(self, y):
""" x.__rlshift__(y) <==> y<<x """
pass
def __rmod__(self, y):
""" x.__rmod__(y) <==> y%x """
pass
def __rmul__(self, y):
""" x.__rmul__(y) <==> y*x """
pass
def __ror__(self, y):
""" x.__ror__(y) <==> y|x """
pass
def __rpow__(self, x, z=None):
""" y.__rpow__(x[, z]) <==> pow(x, y[, z]) """
pass
def __rrshift__(self, y):
""" x.__rrshift__(y) <==> y>>x """
pass
def __rshift__(self, y):
""" x.__rshift__(y) <==> x>>y """
pass
def __rsub__(self, y):
""" x.__rsub__(y) <==> y-x """
pass
def __rtruediv__(self, y):
""" x.__rtruediv__(y) <==> y/x """
pass
def __rxor__(self, y):
""" x.__rxor__(y) <==> y^x """
pass
def __sub__(self, y):
""" x.__sub__(y) <==> x-y """
pass
def __truediv__(self, y):
""" x.__truediv__(y) <==> x/y """
pass
def __trunc__(self, *args, **kwargs):
""" 返回数值被截取为整形的值，在整形中无意义 """
pass
def __xor__(self, y):
""" x.__xor__(y) <==> x^y """
pass
denominator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 分母 = 1 """
"""the denominator of a rational number in lowest terms"""
imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 虚数，无意义 """
"""the imaginary part of a complex number"""
numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 分子 = 数字大小 """
"""the numerator of a rational number in lowest terms"""
real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
""" 实属，无意义 """
"""the real part of a complex number"""
int
num=4 #相当于 num = int(4),其实实际是调用的 __init__()方法 print(int('0b100',0))#输出4,0b100的十进制是4 len_a = a.bit_length() print(len_a) #结果返回3，因为4的2进制为100，最少用3位可以表示 n = 123 #实际是调用了 n = int(123) ,而python内部实际调用了int.__init__方法 print(int('0b100',0))#输出4,0b100的十进制是4
查询变量指向的地址：id(变量名）
在通常程序语言中，变量n1和n2是指向不同的内存地址：
n1 = 123 n2 = 123
而下面代码表示指向同一内存地址：
n1 = 123 n2 = n1
而在python中为了优化内存空间使用，把经常使用的int类型的变量范围-5~257这个范围的变量指向的值，只要值相等则都指向同一内存地址：
最新版本的python，只要值相同则都指向同一内存地址。
n1 = 20 n2 = 20 print(id(n1),id(n2)) #结果返回1802282688 1802282688表示使用的是同一内存地址
2、布尔类型（bool）
True 除0以外的任何值都表示Ture
False 0值表示为False
3、字符串(str)
1)可以用索引和切片、字符串长度
#!usr/bin/env python # -*- coding:utf-8 -*- st = 'congratulations' s1 = st[0] #返回c s2 = st[1] #返回o s3 = st[2] #返回n s4 = st[0:2] #返回co,不包含2 s5 = st[-1] #返回字符串的最后一个字符s #循环输出,每一个字符 for i in st: print(i) print(len(st)) #长度返回15
切片补充：
st = "我们都有一个家名字叫中国" #普通切片 #切出“一个家” s = st[4:7] #注意是顾头不顾腚， #切出“我们” s = st[:2] #从头开始切可以省略0 #切出“都有一个家名字叫中国” s = st[2:] #切到最后冒号后面的数字可以省略 #切出最后两个字 s = st[-2:] #注意不能是-1，因为顾头不顾腚取不到-1 #切出全部字符 s = st[:] #数字省略表示从头切到尾 #切片语法： #s[起始位置:结束位置:步长] 步长是指每几个取一个 #切出“我都一家字中” s = st[::2] #每两个取一个 #步长为负数可以反着取 #切出“家一都” s = st[6:1:-2] #从6到1反着每两个取一个，注意此时一样顾头不顾腚取不到1 #切出“国中叫字名家个一有都们我” s = st[::-1] #从尾到头反着每一个取一个
2)所有字符串功能简介代码如下：
str1.capitalize() #首字母大写
'the title is good'.title()#返回The Title Is Good，每个单词开头的第一个字母变为大写
"YouAre".swapcase() #结果返回yOUaRE，大写变小写，小写变大写
str1.count('u')#字符串str1中u的个数，后面可以加strt参数和end参数
str_unicode = str1.decode('utf-8')#str1从utf-8解码为unicode
str_gbk = str_unicode.encode('gbk') #strr_unicode编码为gbk
str1.find('s')#查询s在str1中的索引位置，可以选择start和end范围，找不到返回-1
'aa_bb_cc'.rfind('_') #结果返回5，返回最高的索引，后面可以加start和end参数
str1.index('s')#查询s在str1中的索引位置，可以选择start和end范围，找不到返回报错
'aa_bb_cc'.rindex('_') #结果返回5，返回最高的索引，后面可以加start和end参数,如果查询不到则抛出异常
'your name is {0} and your age is {1}'.format('sunshuhai','30') #结果your name is sunshuhai and your age is 30
str1.endswith('i')#以字符串i结束，返回True或False,参数可以是元组，元组中的任何一个结束则返回True，后面可以加strt参数和end参数
str1.startswith('i')#以字符串i结束，返回True或False,参数可以是元组，元组中的任何一个结束则返回True，后面可以加strt参数和end参数
str1.isalnum()#(alphanumeric字母数字的)判断是否是字母或数字，至少有一个字符。返回True或False
str1.isalpha()#(alphabetic字母的)判断是否全是字母，至少有一个字符。返回True或False
str1.isdigit()#判断是否全是数字，至少有一个字符。返回True或False
str1.isspace()#判断是否全是空白的（包含换行，tab等），至少有一个字符。返回True或False
'The Title Is Good'.istitle()#判断是否是否是标题字符串（首字母大写），至少有一个字符。返回True或False
str1.islower()#判断是否全是小写字母，至少有一个字符。返回True或False
str1.isupper()#判断是否全是大写字母，至少有一个字符。返回True或False
'abc'.upper() #全部转化为大写
str1.lower() #字符串str1全部转化为小写
'tttTitle'.lstrip('t') #剥除字符串左边的字符t,如果没有参数则删除空格
'tttTitle'.rstrip('t') #剥除字符串右边的字符t,如果没有参数则删除空格
'tttTitle'.strip('t') #剥除字符串两边的字符t,如果没有参数则删除空格
str1.center(20,"*") #sun在中间剩余的17个字符用*号填充，如果*s省略则默认空格
str1.expandtabs(20)#将tab替换为20个空格，如果省略则默认8个空格
str1.ljust(20,'*') #（justified）str1显示在左边，20个字符剩余的位置全部用*填充，*省略默认空格
str1.rjust(20,'*') #（justified）str1显示在右边，20个字符剩余的位置全部用*填充，*省略默认空格
'abc'.zfill(10) #返回0000000abc，如果参数是2返回abc，原字符串不会被截取
'aa_bb_cc'.split('_') #分隔，返回['aa', 'bb', 'cc']，返回列表，不包含分隔符本身，如果省略则用任意空白符分隔
'aa_bb_cc'.rsplit('_') #分隔，返回['aa', 'bb', 'cc']，返回列表，不包含分隔符本身，如果省略则用任意空白符分隔
str1.splitlines(True) #按换行符进行分隔，如果参数省略则列表结果中不包含换行符，如果为True则表示结果包含换行符['zhang\n', 'li\n', 'sun\n', 'zhao\n', 'qian\n']
'aa_bb_cc'.partition('_') #分隔，返回('aa', '_', 'bb_cc')，返回元组包含前，自己，中，自己，后几部分
'aa_bb_cc'.rpartition('_') #分隔，返回('aa_bb', '_', 'cc')，返回元组包含前，自己，中，自己，后几部分
'|'.join(['sun','li','zhao','qian']) #将列表中的元素以|为分隔符连接起来，参数必须是可迭代的
'aa_bb_cc'.replace('_','-',1) #结果返回aa-bb_cc，如果第3个参数表示从左边开始替换几个，不提供，则表示全部替换
translate 需扩展用法
3)补充
isdecimal
python中str函数isdigit、isdecimal、isnumeric的区别 num = "1" #unicode num.isdigit() # True num.isdecimal() # True num.isnumeric() # True num = "1" # 全角 num.isdigit() # True num.isdecimal() # True num.isnumeric() # True num = b"1" # byte num.isdigit() # True num.isdecimal() # AttributeError 'bytes' object has no attribute 'isdecimal' num.isnumeric() # AttributeError 'bytes' object has no attribute 'isnumeric' num = "IV" # 罗马数字 num.isdigit() # True num.isdecimal() # False num.isnumeric() # True num = "四" # 汉字 num.isdigit() # False num.isdecimal() # False num.isnumeric() # True
isidentifier() ：如果字符串是有效的 Python 标识符返回 True，否则返回 False。
#!/usr/bin/env python #-*- encoding:utf-8 -*- print( "if".isidentifier() ) print( "def".isidentifier() ) print( "class".isidentifier() ) print( "_a".isidentifier() ) print( "中国123a".isidentifier() ) print( "123".isidentifier() ) print( "3a".isidentifier() ) print( "".isidentifier() ) 输出结果为： True True True True True False False False
translate
#!/usr/bin/python from string import maketrans # 引用 maketrans 函数。 intab = "aeiou" outtab = "12345" trantab = maketrans(intab, outtab) str = "this is string example....wow!!!" print str.translate(trantab) #输出结果：th3s 3s str3ng 2x1mpl2....w4w!!!
注：Python3.4已经没有string.maketrans()了，取而代之的是内建函数: bytearray.maketrans()、bytes.maketrans()、str.maketrans()
4）字符串归整
遗漏：rstrip lstrip strip
输出中文姓名的2进制编码
name = '张三' #utf-8一个汉字是3个字节，gbk一个汉字是2个字节，一个字节是8个bit
for i in name:
print(i)
byte_list = bytes(i,'utf-8') #bytes('张','utf-8')将张转化为16进制的utf-8字节码列表（集合）
print(str(byte_list,'utf-8')) #将utf-8的字节转化为字符串
print(byte_list) #b'\xe5\xbc\xa0' b'\xe4\xb8\x89',\x表示16禁止，一个16禁止表示4个2进制
for i in byte_list: #循环每个字节时返回每个字节10进制数
print(i,bin(i)) #bin(i) 将10进制转化为2进制
3）、所有str类的函数详细功能，如下代码
class str(basestring):
"""
str(object='') -> string
Return a nice string representation of the object.
If the argument is a string, the return value is the same object.
"""
def capitalize(self):
""" 首字母变大写 """
"""
S.capitalize() -> string
Return a copy of the string S with only its first character
capitalized['k?pit?laizd]大写的
返回一个复制的只是第一个字符大写的字符串
""" return ""
def center(self, width, fillchar=None):
""" 内容居中，width：总长度；fillchar：空白处填充内容，默认无 """
"""
S.center(width[, fillchar]) -> string
Return S centered in a string of length width. Padding is
done using the specified fill character (default is a space)
返回S字符串参数width长度的中间，用规定的字符进行填补（默认是空格）
"""
return ""
def count(self, sub, start=None, end=None):
""" 子序列个数 """
"""
S.count(sub[, start[, end]]) -> int
Return the number of non-overlapping occurrences of substring sub in
string S[start:end]. Optional arguments start and end are interpreted
as in slice notation.
返回非重叠发生的子字符串序列sub在字符串范围start和end参数之间的个数，可选择参数start和end可以理解为切片
"""
return 0
def decode(self, encoding=None, errors=None):
""" 解码 """
"""
S.decode([encoding[,errors]]) -> object
Decodes S using the codec registered for encoding. encoding defaults
to the default encoding. errors may be given to set a different error
handling scheme. Default is 'strict' meaning that encoding errors raise
a UnicodeDecodeError. Other possible values are 'ignore' and 'replace'
as well as any other name registered with codecs.register_error that is
able to handle UnicodeDecodeErrors.
"""
return object()
def encode(self, encoding=None, errors=None):
""" 编码，针对unicode """
"""
S.encode([encoding[,errors]]) -> object
Encodes S using the codec registered for encoding. encoding defaults
to the default encoding. errors may be given to set a different error
handling scheme. Default is 'strict' meaning that encoding errors raise
a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and
'xmlcharrefreplace' as well as any other name registered with
codecs.register_error that is able to handle UnicodeEncodeErrors.
"""
return object()
def endswith(self, suffix, start=None, end=None):
""" 是否以 xxx 结束 """
"""
S.endswith(suffix[, start[, end]]) -> bool
Return True if S ends with the specified suffix, False otherwise.
With optional start, test S beginning at that position.
With optional end, stop comparing S at that position.
suffix can also be a tuple of strings to try.
返回True如果以规定的参数suffix结束，否则返回False
选择参数start,那么字符串从这个位置开始
选择参数end,那么从这个位置停止比较字符串
suffix可能是一个字符串类型的元祖
"""
return False
def expandtabs(self, tabsize=None):
""" 将tab转换成空格，默认一个tab转换成8个空格 """
"""
S.expandtabs([tabsize]) -> string
Return a copy of S where all tab characters are expanded using spaces.
If tabsize is not given, a tab size of 8 characters is assumed.
返回一个赋值的字符串，该字符串所有的tab字符全部扩展为空格
如果tabsize没提供，自动嘉定一个tab大小为8个字符
"""
return ""
def find(self, sub, start=None, end=None):
""" 寻找子序列位置，如果没找到，返回 -1 """
"""
S.find(sub [,start [,end]]) -> int
Return the lowest index in S where substring sub is found,
such that sub is contained within S[start:end]. Optional
arguments start and end are interpreted as in slice notation.
如果那个sub包含在字符串start和end之内。选择
参数start和end被理解为切片
Return -1 on failure.
返回在字符串sub被找到的最小索引，
失败的话返回-1
"""
return 0
def format(*args, **kwargs): # known special case of str.format
""" 字符串格式化，动态参数，将函数式编程时细说 """
"""
S.format(*args, **kwargs) -> string
Return a formatted version of S, using substitutions from args and kwargs.
The substitutions are identified by braces ('{' and '}').
返回格式化版本的字符串，用args和kwargs参数代替。
这个替代可以被大括号识别
"""
pass
def index(self, sub, start=None, end=None):
""" 子序列位置，如果没找到，报错 """
S.index(sub [,start [,end]]) -> int
"""
Like S.find() but raise ValueError when the substring is not found.
像find函数，但是当子字符串找不到时会抛出ValueError是我错误
"""
return 0
def isalnum(self):
""" 是否是字母和数字 """
"""
S.isalnum() -> bool
Return True if all characters in S are alphanumeric
and there is at least one character in S, False otherwise.
返回真，如果所有在字符串中的字符是字母或数字的
并且至少在字符串中有一个字符，否则返回False
"""
return False
def isalpha(self):
""" 是否是字母 """
"""
S.isalpha() -> bool
Return True if all characters in S are alphabetic
and there is at least one character in S, False otherwise.
返回True，如果所有的字符都是字母
并且至少有一个字符在字符串中，否则返回False
"""
return False
def isdigit(self):
""" 是否是数字 """
"""
S.isdigit() -> bool
Return True if all characters in S are digits
and there is at least one character in S, False otherwise.
返回True如果所有的字符都是数字
并且至少有一个字符，否则返回False
"""
return False
def islower(self):
""" 是否小写 """
"""
S.islower() -> bool
Return True if all cased characters in S are lowercase and there is
at least one cased character in S, False otherwise.
返回True如果所有的字母字符都是小写字母并且
至少有一个字符字母在字符串中，否则返回False
"""
return False
def isspace(self):
"""
S.isspace() -> bool
Return True if all characters in S are whitespace
and there is at least one character in S, False otherwise.
返回True如果所有的字符都是空白的（包含换行，tab等）
并且失少有一个字符，否则返回False
"""
return False
def istitle(self):
"""
S.istitle() -> bool
Return True if S is a titlecased string and there is at least one
character in S, i.e. uppercase characters may only follow uncased
characters and lowercase characters only cased ones. Return False
otherwise.
返回True如果字符串中是一个标题字母字符串（并且至少一个字符，
也就是大写字母可能只是外漏的字母，其他是小写字母（首字母大写）
"""
return False
def isupper(self):
"""
S.isupper() -> bool
Return True if all cased characters in S are uppercase and there is
at least one cased character in S, False otherwise.
返回True如果所有的字母都是大写字母
至少有一个字母字符在字符串中，否则返回False
"""
return False
def join(self, iterable):
""" 连接 """
"""
S.join(iterable) -> string
Return a string which is the concatenation of the strings in the
iterable. The separator between elements is S.
返回一个字符串，该字符串连接迭代器中的字符串，元素直接的分隔符是‘S’
支持列表 元组之间的连接
"""
return ""
def ljust(self, width, fillchar=None):
""" 内容左对齐，右侧填充 """
"""
S.ljust(width[, fillchar]) -> string
Return S left-justified in a string of length width. Padding is
done using the specified fill character (default is a space).
返回左调整在字符串width的长度中，用规定的字符进行填充（默认是空格）
字符显示在左边，其余全部被填充
"""
return ""
def lower(self):
""" 变小写 """
"""
S.lower() -> string
Return a copy of the string S converted to lowercase.
返回一个赋值的字符串转为小写
"""
return ""
def lstrip(self, chars=None):
""" 移除左侧空白 """
"""
S.lstrip([chars]) -> string or unicode
Return a copy of the string S with leading whitespace removed.
If chars is given and not None, remove characters in chars instead.
If chars is unicode, S will be converted to unicode before stripping
返回一个赋值的字符串，该字符串开头空格被移除
如果chars参数被给予并且不是None值，那么删除参数chars代指的字符
如果chars是unicode,S 将转化成unicode在删除之前
"""
return ""
def partition(self, sep):
""" 分割，前，中，后三部分 """
"""
S.partition(sep) -> (head, sep, tail)
Search for the separator sep in S, and return the part before it,
the separator itself, and the part after it. If the separator is not
found, return S and two empty strings.
查找分隔符参数sep，并返回它之前的部分，
分隔符自己，和分隔符之后的部分。如果分隔符找不到，
返回两个空字符串
"""
pass
def replace(self, old, new, count=None):
""" 替换 """
"""
S.replace(old, new[, count]) -> string
Return a copy of string S with all occurrences of substring
old replaced by new. If the optional argument count is
given, only the first count occurrences are replaced.
返回一个赋值的字符串，已经发生的老字符串被新字符串替换。如果选择参数count被提供了，
只有第一个count已发生的被替换
"""
return ""
def rfind(self, sub, start=None, end=None):
"""
S.rfind(sub [,start [,end]]) -> int
Return the highest index in S where substring sub is found,
such that sub is contained within S[start:end]. Optional
arguments start and end are interpreted as in slice notation.
Return -1 on failure.
返回最高的索引如果sub在子字符串中被找到
如果sub参数包含在start和end之间，选择参数start和end被理解为切片
如果查找不到则返回-1
"""
return 0
def rindex(self, sub, start=None, end=None):
"""
S.rindex(sub [,start [,end]]) -> int
Like S.rfind() but raise ValueError when the substring is not found.
和rfind()函数一行，但是当在字符串中找不到的是否抛出ValueError异常
"""
return 0
def rjust(self, width, fillchar=None):
"""
S.rjust(width[, fillchar]) -> string
Return S right-justified in a string of length width. Padding is
done using the specified fill character (default is a space)
返回字符串长度在参数width中的右调整字符串
用规定的字符填补（默认是空格）
字符显示在右边，其余全部被填充
"""
return ""
def rpartition(self, sep):
"""
S.rpartition(sep) -> (head, sep, tail)
Search for the separator sep in S, starting at the end of S, and return
the part before it, the separator itself, and the part after it. If the
separator is not found, return two empty strings and S.
查找分隔符参数set，从字符串的末尾开始，返回之前的部分，返回分隔符本身，返回后半部分，
如果分隔符找不到，返回两个空的字符串
"""
pass
def rsplit(self, sep=None, maxsplit=None):
"""
S.rsplit([sep [,maxsplit]]) -> list of strings
Return a list of the words in the string S, using sep as the
delimiter string, starting at the end of the string and working
to the front. If maxsplit is given, at most maxsplit splits are
done. If sep is not specified or is None, any whitespace string
is a separator.
返回一个单词列表在字符串中，把sep用做分隔符，起始于字符创的末尾，并且作用于
前面。如果maxsplit参数提供了，最多分隔几次被设定，
如果sep没有规定或者是None,任何空白字符就是这个分隔符
"""
return []
def rstrip(self, chars=None):
"""
S.rstrip([chars]) -> string or unicode
Return a copy of the string S with trailing whitespace removed.
If chars is given and not None, remove characters in chars instead.
If chars is unicode, S will be converted to unicode before stripping
返回一个复制的字符串，该字符串后面的空格符被移除。
如果chars参数被给予并且不是None值，移除字符chars代替
如果chars是unicode,字符串将转为unicode在剥除之前
"""
return ""
def split(self, sep=None, maxsplit=None):
""" 分割， maxsplit最多分割几次 """
"""
S.split([sep [,maxsplit]]) -> list of strings
Return a list of the words in the string S, using sep as the
delimiter string. If maxsplit is given, at most maxsplit
splits are done. If sep is not specified or is None, any
whitespace string is a separator and empty strings are removed
from the result.
返回一个单词列表在字符串中，把sep用做分隔符，如果maxsplit参数提供了，
最多分隔此时确定。如果sep参数没有指定或者为None,
任何空白符就是分隔符并且空字符串从结果中移除
"""
return []
def splitlines(self, keepends=False):
""" 根据换行分割 """
"""
S.splitlines(keepends=False) -> list of strings
Return a list of the lines in S, breaking at line boundaries.
Line breaks are not included in the resulting list unless keepends
is given and true.
返回一个行的列表，阻断在行边界。
行中断不包含列表结果中，除非keepends参数提供了并且为True
"""
return []
def startswith(self, prefix, start=None, end=None):
""" 是否起始 """
"""
S.startswith(prefix[, start[, end]]) -> bool
Return True if S starts with the specified prefix, False otherwise.
With optional start, test S beginning at that position.
With optional end, stop comparing S at that position.
prefix can also be a tuple of strings to try.
返回True 如果开始于指定的参数prefix否则返回False
带start参数，从那个位置开始检测
带end参数，至那个位置停止比较
"""
return False
def strip(self, chars=None):
""" 移除两段空白 """
"""
S.strip([chars]) -> string or unicode
Return a copy of the string S with leading and trailing
whitespace removed.
If chars is given and not None, remove characters in chars instead.
If chars is unicode, S will be converted to unicode before stripping
返回一个复制的字符串，该字符串头部和尾部
的空白字符被移除
如果chars参数被提供并且不为None，移除字符用参数chars代替
如果chars是unicode,字符串将被转化为unicode在剥除之前
"""
return ""
def swapcase(self):
""" 大写变小写，小写变大写 """
"""
S.swapcase() -> string
Return a copy of the string S with uppercase characters
converted to lowercase and vice versa.
返回一个复制的字符串，改字符串大写字母字符转化为小写字母，
反之亦然
"""
return ""
def title(self):
"""
S.title() -> string
Return a titlecased version of S, i.e. words start with uppercase
characters, all remaining cased characters have lowercase.
返回一个标题版本字符串，也是就单词开始是大写字符，所有剩余的字符字符都是小写
"""
return ""
def translate(self, table, deletechars=None):
"""
转换，需要先做一个对应表，最后一个表示删除字符集合
intab = "aeiou"
outtab = "12345"
trantab = maketrans(intab, outtab)
str = "this is string example....wow!!!"
print str.translate(trantab, 'xm')
"""
"""
S.translate(table [,deletechars]) -> string
Return a copy of the string S, where all characters occurring
in the optional argument deletechars are removed, and the
remaining characters have been mapped through the given
translation table, which must be a string of length 256 or None.
If the table argument is None, no translation is applied and
the operation simply removes the characters in deletechars.
返回一个复制的字符串，该字符串所有的字符
出现在选择参数deletechars中被移除，并且
剩余的字符已经通过映射规定的翻译表，该表必须是个长度为256的字符串或者是None。
如果表的参数为None，没有翻译表应用并且简单的操作移除了在deletechars中的字符
"""
return ""
def upper(self):
"""
S.upper() -> string
Return a copy of the string S converted to uppercase.
返回一个复制的转化为大写的字符串
"""
return ""
def zfill(self, width):
"""方法返回指定长度的字符串，原字符串右对齐，前面填充0。"""
"""
S.zfill(width) -> string
Pad a numeric string S with zeros on the left, to fill a field
of the specified width. The string S is never truncated.
在左边填补0，填充制定参数width的制定宽度。原字符串不会截取
"""
return ""
def _formatter_field_name_split(self, *args, **kwargs): # real signature unknown
pass
def _formatter_parser(self, *args, **kwargs): # real signature unknown
pass
def __add__(self, y):
""" x.__add__(y) <==> x+y """
pass
def __contains__(self, y):
""" x.__contains__(y) <==> y in x """
pass
def __eq__(self, y):
""" x.__eq__(y) <==> x==y """
pass
def __format__(self, format_spec):
"""
S.__format__(format_spec) -> string
Return a formatted version of S as described by format_spec.
"""
return ""
def __getattribute__(self, name):
""" x.__getattribute__('name') <==> x.name """
pass
def __getitem__(self, y):
""" x.__getitem__(y) <==> x[y] """
pass
def __getnewargs__(self, *args, **kwargs): # real signature unknown
pass
def __getslice__(self, i, j):
"""
x.__getslice__(i, j) <==> x[i:j]
Use of negative indices is not supported.
"""
pass
def __ge__(self, y):
""" x.__ge__(y) <==> x>=y """
pass
def __gt__(self, y):
""" x.__gt__(y) <==> x>y """
pass
def __hash__(self):
""" x.__hash__() <==> hash(x) """
pass
def __init__(self, string=''): # known special case of str.__init__
"""
str(object='') -> string
Return a nice string representation of the object.
If the argument is a string, the return value is the same object.
# (copied from class doc)
"""
pass
def __len__(self):
""" x.__len__() <==> len(x) """
pass
def __le__(self, y):
""" x.__le__(y) <==> x<=y """
pass
def __lt__(self, y):
""" x.__lt__(y) <==> x<y """
pass
def __mod__(self, y):
""" x.__mod__(y) <==> x%y """
pass
def __mul__(self, n):
""" x.__mul__(n) <==> x*n """
pass
@staticmethod # known case of __new__
def __new__(S, *more):
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass
def __ne__(self, y):
""" x.__ne__(y) <==> x!=y """
pass
def __repr__(self):
""" x.__repr__() <==> repr(x) """
pass
def __rmod__(self, y):
""" x.__rmod__(y) <==> y%x """
pass
def __rmul__(self, n):
""" x.__rmul__(n) <==> n*x """
pass
def __sizeof__(self):
""" S.__sizeof__() -> size of S in memory, in bytes """
pass
def __str__(self):
""" x.__str__() <==> str(x) """
pass
str
