Python之路【第五篇】：Python基本数据类型

type函数

利用type()函数可以查看数据的类型，比如说是str类型，在编辑器中写上str,按住ctrl,点击str，

就到了源码定义的部分，所有str的功能都在这里了，同样，对于一个str变量temp,temp.upper()，
按住ctrl，点击temp.upper()也跳到了这个功能的说明部分
所有字符串或者数字、字典等数据类型所具备的方法都存在相对应的类里面

查看对象的类，或对象所具备的功能
1、可以利用type查看类型，利用ctrl+鼠标左键
2、利用dir(对象名字),可以查看该类对象所具有的功能名字
3、help(对象名字)或者help(type(对象名字))，可以查看详细说明
4、直接ctrl+鼠标左键点击方法名字，便会自动定位到功能处

下面是对数据类型中的一些函数进行说明，只说了一些不太好理解的函数
在函数的源码里面，如果括号中只有一个self，就表示不用传参数

dir()函数

　　　　见type函数部分

help()函数

　　　　见type函数部分

强制类型转换

　　　　数据类型(变量)，例如，有一个str型变量temp，将其转换成int型：

　　　　int(temp)

数据类型中，字符串、列表、字典无疑是最重要的

数字

int型变量

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

int型变量的创建：

• n1 = 123
• n2 = int(123)

类里面有一个__init__方法，类名（）这种形式实际上就是调用了该方法，通过查看源码我们也看到，int('0ff',16)，这样可以将16进制转化为10进制，这个知道就好了

还有就是类里面带有下划线的方法是自动调用的，在学习到类的时候会有详述

思考一个问题：n1=123,n2=123与n1=123,n2=n1有何区别？

答：n1=123,n2=123是指向内存中的两块区域，n1=123,n2=n1指向内存中的一块区域，但是在python内部，为了内存优化，在一个数值范围内(-5~257)，都是指向一块内存。可以用过id(n1)与id(n2)来查看内存地址

python真的很人性化，之前的一些编程语言，整数大小分为多种，但是在python中，在低版本中，还会考虑数据的长度问题，32位机器： -2**31~2**31 ，64位机器：-2**63~2**63-1，如果超出了这个范围，python内部会自动变为long类型,而long是电脑多牛逼，long就有多大，所以在python中使用int，不用担心长度的限制，但是在3的版本中，就没有这个限制了，int就是无限长了，再也不用考虑长度问题了，爽爆了，看下面：

n = 1234567891012312321312312131231231231231
print(n/2327343993898989893493498239489238483248)

输出：0.5304621466567329
是不是感觉爽爆了，哈哈，我喜欢

int类型常用功能剖析:
1、n1+n2 实际是调用n1.__add__(n2)这个方法
2、bit_length()表示该数字的二进制最少可以占用几位

3、输出十进制数字的二进制用bin()方法，具体参考Python之路【第九篇】

class int(object)
 |  int(x=0) -> integer
 |  int(x, base=10) -> integer
 |  
 |  Convert a number or string to an integer, or return 0 if no arguments
 |  are given.  If x is a number, return x.__int__().  For floating point
 |  numbers, this truncates towards zero.
 |  
 |  If x is not a number or if base is given, then x must be a string,
 |  bytes, or bytearray instance 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)
 |  4
 |  
 |  Methods defined here:
 |  
 |  __abs__(self, /)
 |      abs(self)
 |  
 |  __add__(self, value, /)
 |      Return self+value.
 |  
 |  __and__(self, value, /)
 |      Return self&value.
 |  
 |  __bool__(self, /)
 |      self != 0
 |  
 |  __ceil__(...)
 |      Ceiling of an Integral returns itself.
 |  
 |  __divmod__(self, value, /)
 |      Return divmod(self, value).
 |  
 |  __eq__(self, value, /)
 |      Return self==value.
 |  
 |  __float__(self, /)
 |      float(self)
 |  
 |  __floor__(...)
 |      Flooring an Integral returns itself.
 |  
 |  __floordiv__(self, value, /)
 |      Return self//value.
 |  
 |  __format__(...)
 |      default object formatter
 |  
 |  __ge__(self, value, /)
 |      Return self>=value.
 |  
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |  
 |  __getnewargs__(...)
 |  
 |  __gt__(self, value, /)
 |      Return self>value.
 |  
 |  __hash__(self, /)
 |      Return hash(self).
 |  
 |  __index__(self, /)
 |      Return self converted to an integer, if self is suitable for use as an index into a list.
 |  
 |  __int__(self, /)
 |      int(self)
 |  
 |  __invert__(self, /)
 |      ~self
 |  
 |  __le__(self, value, /)
 |      Return self<=value.
 |  
 |  __lshift__(self, value, /)
 |      Return self<<value.
 |  
 |  __lt__(self, value, /)
 |      Return self<value.
 |  
 |  __mod__(self, value, /)
 |      Return self%value.
 |  
 |  __mul__(self, value, /)
 |      Return self*value.
 |  
 |  __ne__(self, value, /)
 |      Return self!=value.
 |  
 |  __neg__(self, /)
 |      -self
 |  
 |  __new__(*args, **kwargs) from builtins.type
 |      Create and return a new object.  See help(type) for accurate signature.
 |  
 |  __or__(self, value, /)
 |      Return self|value.
 |  
 |  __pos__(self, /)
 |      +self
 |  
 |  __pow__(self, value, mod=None, /)
 |      Return pow(self, value, mod).
 |  
 |  __radd__(self, value, /)
 |      Return value+self.
 |  
 |  __rand__(self, value, /)
 |      Return value&self.
 |  
 |  __rdivmod__(self, value, /)
 |      Return divmod(value, self).
 |  
 |  __repr__(self, /)
 |      Return repr(self).
 |  
 |  __rfloordiv__(self, value, /)
 |      Return value//self.
 |  
 |  __rlshift__(self, value, /)
 |      Return value<<self.
 |  
 |  __rmod__(self, value, /)
 |      Return value%self.
 |  
 |  __rmul__(self, value, /)
 |      Return value*self.
 |  
 |  __ror__(self, value, /)
 |      Return value|self.
 |  
 |  __round__(...)
 |      Rounding an Integral returns itself.
 |      Rounding with an ndigits argument also returns an integer.
 |  
 |  __rpow__(self, value, mod=None, /)
 |      Return pow(value, self, mod).
 |  
 |  __rrshift__(self, value, /)
 |      Return value>>self.
 |  
 |  __rshift__(self, value, /)
 |      Return self>>value.
 |  
 |  __rsub__(self, value, /)
 |      Return value-self.
 |  
 |  __rtruediv__(self, value, /)
 |      Return value/self.
 |  
 |  __rxor__(self, value, /)
 |      Return value^self.
 |  
 |  __sizeof__(...)
 |      Returns size in memory, in bytes
 |  
 |  __str__(self, /)
 |      Return str(self).
 |  
 |  __sub__(self, value, /)
 |      Return self-value.
 |  
 |  __truediv__(self, value, /)
 |      Return self/value.
 |  
 |  __trunc__(...)
 |      Truncating an Integral returns itself.
 |  
 |  __xor__(self, value, /)
 |      Return self^value.
 |  
 |  bit_length(...)
 |      int.bit_length() -> int
 |      
 |      Number of bits necessary to represent self in binary.
 |      >>> bin(37)
 |      '0b100101'
 |      >>> (37).bit_length()
 |      6
 |  
 |  conjugate(...)
 |      Returns self, the complex conjugate of any int.
 |  
 |  from_bytes(...) from builtins.type
 |      int.from_bytes(bytes, byteorder, *, signed=False) -> int
 |      
 |      Return the integer represented by the given array of bytes.
 |      
 |      The bytes argument must be a bytes-like object (e.g. bytes or bytearray).
 |      
 |      The byteorder argument determines the byte order used to represent the
 |      integer.  If byteorder is 'big', the most significant byte is at the
 |      beginning of the byte array.  If byteorder is 'little', the most
 |      significant byte is at the end of the byte array.  To request the native
 |      byte order of the host system, use `sys.byteorder' as the byte order value.
 |      
 |      The signed keyword-only argument indicates whether two's complement is
 |      used to represent the integer.
 |  
 |  to_bytes(...)
 |      int.to_bytes(length, byteorder, *, signed=False) -> bytes
 |      
 |      Return an array of bytes representing an integer.
 |      
 |      The integer is represented using length bytes.  An OverflowError is
 |      raised if the integer is not representable with the given number of
 |      bytes.
 |      
 |      The byteorder argument determines the byte order used to represent the
 |      integer.  If byteorder is 'big', the most significant byte is at the
 |      beginning of the byte array.  If byteorder is 'little', the most
 |      significant byte is at the end of the byte array.  To request the native
 |      byte order of the host system, use `sys.byteorder' as the byte order value.
 |      
 |      The signed keyword-only argument determines whether two's complement is
 |      used to represent the integer.  If signed is False and a negative integer
 |      is given, an OverflowError is raised.
 |  
 |  ----------------------------------------------------------------------
 |  Data descriptors defined here:
 |  
 |  denominator
 |      the denominator of a rational number in lowest terms
 |  
 |  imag
 |      the imaginary part of a complex number
 |  
 |  numerator
 |      the numerator of a rational number in lowest terms
 |  
 |  real
 |      the real part of a complex number

bytes类型：

　　　　在2.7中没有，在3里面才有，将字符转换成字节，返回一个字节的集合，所以说3真的是很强大，具体可以参考Python之路【第九篇】

布尔值

True　　真

False　  假

字符串(str)

字符串的创建：

s1 = 'asd'
s2 = str()创建一个空字符串
s3 = str('asd')创建一个普通的字符串
s4 = str(字节类型，编码)，如b_gbk = bytes(s,encoding='gbk')        str(b_gbk,encoding='gbk')

str类型常用功能剖析:
1、format()，format()中接受的参数，依次传递给字符串中的占位符{0}，{1}，{2}，如：s='hello,{0},I {1} you',s.format('python','love')
最后s就变成hello python,I love you有几个占位符就要给format()传递几个参数
2、join()，如lst=['h','e','l','l','o'],执行'_'.join(lst)后得到h_e_l_l_o
3、lstrip()移除字符串中左边的空格
4、rstrip()移除字符串中右边的空格
5、strip()移除字符串中的左边跟右边的空格
6、partition()将字符串进行分割
7、replace()对指定的内容进行替换
8、split()对字符串进行分割
9、索引 s='abcde',s[0]表示第一个字符，s[1]表示第二个字符，依此类推，len(s)用来获取字符串的长度，即字符个数
10、切片s[n:m] n=<*<m

class str(object)
 |  str(object='') -> str
 |  str(bytes_or_buffer[, encoding[, errors]]) -> str
 |  
 |  Create a new string object from the given object. If encoding or
 |  errors is specified, then the object must expose a data buffer
 |  that will be decoded using the given encoding and error handler.
 |  Otherwise, returns the result of object.__str__() (if defined)
 |  or repr(object).
 |  encoding defaults to sys.getdefaultencoding().
 |  errors defaults to 'strict'.
 |  
 |  Methods defined here:
 |  
 |  __add__(self, value, /)
 |      Return self+value.
 |  
 |  __contains__(self, key, /)
 |      Return key in self.
 |  
 |  __eq__(self, value, /)
 |      Return self==value.
 |  
 |  __format__(...)
 |      S.__format__(format_spec) -> str
 |      
 |      Return a formatted version of S as described by format_spec.
 |  
 |  __ge__(self, value, /)
 |      Return self>=value.
 |  
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |  
 |  __getitem__(self, key, /)
 |      Return self[key].
 |  
 |  __getnewargs__(...)
 |  
 |  __gt__(self, value, /)
 |      Return self>value.
 |  
 |  __hash__(self, /)
 |      Return hash(self).
 |  
 |  __iter__(self, /)
 |      Implement iter(self).
 |  
 |  __le__(self, value, /)
 |      Return self<=value.
 |  
 |  __len__(self, /)
 |      Return len(self).
 |  
 |  __lt__(self, value, /)
 |      Return self<value.
 |  
 |  __mod__(self, value, /)
 |      Return self%value.
 |  
 |  __mul__(self, value, /)
 |      Return self*value.n
 |  
 |  __ne__(self, value, /)
 |      Return self!=value.
 |  
 |  __new__(*args, **kwargs) from builtins.type
 |      Create and return a new object.  See help(type) for accurate signature.
 |  
 |  __repr__(self, /)
 |      Return repr(self).
 |  
 |  __rmod__(self, value, /)
 |      Return value%self.
 |  
 |  __rmul__(self, value, /)
 |      Return self*value.
 |  
 |  __sizeof__(...)
 |      S.__sizeof__() -> size of S in memory, in bytes
 |  
 |  __str__(self, /)
 |      Return str(self).
 |  
 |  capitalize(...)
 |      S.capitalize() -> str
 |      
 |      Return a capitalized version of S, i.e. make the first character
 |      have upper case and the rest lower case.
 |  
 |  casefold(...)
 |      S.casefold() -> str
 |      
 |      Return a version of S suitable for caseless comparisons.
 |  
 |  center(...)
 |      S.center(width[, fillchar]) -> str
 |      
 |      Return S centered in a string of length width. Padding is
 |      done using the specified fill character (default is a space)
 |  
 |  count(...)
 |      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.
 |  
 |  encode(...)
 |      S.encode(encoding='utf-8', errors='strict') -> bytes
 |      
 |      Encode S using the codec registered for encoding. Default encoding
 |      is 'utf-8'. 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 can handle UnicodeEncodeErrors.
 |  
 |  endswith(...)
 |      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.
 |  
 |  expandtabs(...)
 |      S.expandtabs(tabsize=8) -> str
 |      
 |      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.
 |  
 |  find(...)
 |      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.
 |      
 |      Return -1 on failure.
 |  
 |  format(...)
 |      S.format(*args, **kwargs) -> str
 |      
 |      Return a formatted version of S, using substitutions from args and kwargs.
 |      The substitutions are identified by braces ('{' and '}').
 |  
 |  format_map(...)
 |      S.format_map(mapping) -> str
 |      
 |      Return a formatted version of S, using substitutions from mapping.
 |      The substitutions are identified by braces ('{' and '}').
 |  
 |  index(...)
 |      S.index(sub[, start[, end]]) -> int
 |      
 |      Like S.find() but raise ValueError when the substring is not found.
 |  
 |  isalnum(...)
 |      S.isalnum() -> bool
 |      
 |      Return True if all characters in S are alphanumeric
 |      and there is at least one character in S, False otherwise.
 |  
 |  isalpha(...)
 |      S.isalpha() -> bool
 |      
 |      Return True if all characters in S are alphabetic
 |      and there is at least one character in S, False otherwise.
 |  
 |  isdecimal(...)
 |      S.isdecimal() -> bool
 |      
 |      Return True if there are only decimal characters in S,
 |      False otherwise.
 |  
 |  isdigit(...)
 |      S.isdigit() -> bool
 |      
 |      Return True if all characters in S are digits
 |      and there is at least one character in S, False otherwise.
 |  
 |  isidentifier(...)
 |      S.isidentifier() -> bool
 |      
 |      Return True if S is a valid identifier according
 |      to the language definition.
 |      
 |      Use keyword.iskeyword() to test for reserved identifiers
 |      such as "def" and "class".
 |  
 |  islower(...)
 |      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.
 |  
 |  isnumeric(...)
 |      S.isnumeric() -> bool
 |      
 |      Return True if there are only numeric characters in S,
 |      False otherwise.
 |  
 |  isprintable(...)
 |      S.isprintable() -> bool
 |      
 |      Return True if all characters in S are considered
 |      printable in repr() or S is empty, False otherwise.
 |  
 |  isspace(...)
 |      S.isspace() -> bool
 |      
 |      Return True if all characters in S are whitespace
 |      and there is at least one character in S, False otherwise.
 |  
 |  istitle(...)
 |      S.istitle() -> bool
 |      
 |      Return True if S is a titlecased string and there is at least one
 |      character in S, i.e. upper- and titlecase characters may only
 |      follow uncased characters and lowercase characters only cased ones.
 |      Return False otherwise.
 |  
 |  isupper(...)
 |      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.
 |  
 |  join(...)
 |      S.join(iterable) -> str
 |      
 |      Return a string which is the concatenation of the strings in the
 |      iterable.  The separator between elements is S.
 |  
 |  ljust(...)
 |      S.ljust(width[, fillchar]) -> str
 |      
 |      Return S left-justified in a Unicode string of length width. Padding is
 |      done using the specified fill character (default is a space).
 |  
 |  lower(...)
 |      S.lower() -> str
 |      
 |      Return a copy of the string S converted to lowercase.
 |  
 |  lstrip(...)
 |      S.lstrip([chars]) -> str
 |      
 |      Return a copy of the string S with leading whitespace removed.
 |      If chars is given and not None, remove characters in chars instead.
 |  
 |  partition(...)
 |      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.
 |  
 |  replace(...)
 |      S.replace(old, new[, count]) -> str
 |      
 |      Return a copy of S with all occurrences of substring
 |      old replaced by new.  If the optional argument count is
 |      given, only the first count occurrences are replaced.
 |  
 |  rfind(...)
 |      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.
 |  
 |  rindex(...)
 |      S.rindex(sub[, start[, end]]) -> int
 |      
 |      Like S.rfind() but raise ValueError when the substring is not found.
 |  
 |  rjust(...)
 |      S.rjust(width[, fillchar]) -> str
 |      
 |      Return S right-justified in a string of length width. Padding is
 |      done using the specified fill character (default is a space).
 |  
 |  rpartition(...)
 |      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.
 |  
 |  rsplit(...)
 |      S.rsplit(sep=None, maxsplit=-1) -> list of strings
 |      
 |      Return a list of the words in 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, any whitespace string
 |      is a separator.
 |  
 |  rstrip(...)
 |      S.rstrip([chars]) -> str
 |      
 |      Return a copy of the string S with trailing whitespace removed.
 |      If chars is given and not None, remove characters in chars instead.
 |  
 |  split(...)
 |      S.split(sep=None, maxsplit=-1) -> list of strings
 |      
 |      Return a list of the words in 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.
 |  
 |  splitlines(...)
 |      S.splitlines([keepends]) -> 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.
 |  
 |  startswith(...)
 |      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.
 |  
 |  strip(...)
 |      S.strip([chars]) -> str
 |      
 |      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.
 |  
 |  swapcase(...)
 |      S.swapcase() -> str
 |      
 |      Return a copy of S with uppercase characters converted to lowercase
 |      and vice versa.
 |  
 |  title(...)
 |      S.title() -> str
 |      
 |      Return a titlecased version of S, i.e. words start with title case
 |      characters, all remaining cased characters have lower case.
 |  
 |  translate(...)
 |      S.translate(table) -> str
 |      
 |      Return a copy of the string S in which each character has been mapped
 |      through the given translation table. The table must implement
 |      lookup/indexing via __getitem__, for instance a dictionary or list,
 |      mapping Unicode ordinals to Unicode ordinals, strings, or None. If
 |      this operation raises LookupError, the character is left untouched.
 |      Characters mapped to None are deleted.
 |  
 |  upper(...)
 |      S.upper() -> str
 |      
 |      Return a copy of S converted to uppercase.
 |  
 |  zfill(...)
 |      S.zfill(width) -> str
 |      
 |      Pad a numeric string S with zeros on the left, to fill a field
 |      of the specified width. The string S is never truncated.
 |  
 |  ----------------------------------------------------------------------
 |  Static methods defined here:
 |  
 |  maketrans(x, y=None, z=None, /)
 |      Return a translation table usable for str.translate().
 |      
 |      If there is only one argument, it must be a dictionary mapping Unicode
 |      ordinals (integers) or characters to Unicode ordinals, strings or None.
 |      Character keys will be then converted to ordinals.
 |      If there are two arguments, they must be strings of equal length, and
 |      in the resulting dictionary, each character in x will be mapped to the
 |      character at the same position in y. If there is a third argument, it
 |      must be a string, whose characters will be mapped to None in the result.

 

列表(list)

　　　　 列表是元素的集合，并且列表中的元素是可变化的

在以后的日子里，有一个约定俗成的东西，写列表的时候最后加一个逗号，比如：[1,2,3,4,5,]

列表的创建;

　　li = [1,2,3,4,]

　　li = list()，创建一个空的列表

　　li = list(可迭代对象)，转换，字符串、元组、字典都是可迭代对象，比如这里的可迭代对象是一个字符串，内部会运行一个for循环，把可迭代对象的元素当作列表的元素，如：　　

 

s = 'hello'
li = list(s)
print(li)
输出结果为：['h', 'e', 'l', 'l', 'o']

dic = {'k1':'as','k2':'dasd'}
print(list(dic.values()))
print(list(dic.items()))
print(list(dic.keys()))
输出结果为：

['dasd', 'as']
[('k2', 'dasd'), ('k1', 'as')]
['k2', 'k1']

 

list类型常用功能剖析:
lst = [1,2,3,'e'],这就是一个列表
len(lst)获取列表长度
列表中的索引、切片、循环跟字符串都是一样的
append(),在列表末尾追加元素，lst.append('s'),则lst=[***,'s']
count(),统计列表中某一个元素的个数
extend()，扩展列表，lst.extend(iterable)，iterable为可迭代对象
index()，获取某个元素的索引
insert()，往某个索引位置插入一个值
pop()，移除一个值，没有参数的，移除尾部的值，但是这个值可以赋给另外一个变量，如a=lst.pop(),就表示将列表中的最后一个元素移除并赋值给a
remove()，移除从左边找到的第一个
reverse()，反转列表
sort()排序
del lst[index]删除索引index处的元素，del lst[index1:index2]

列表的嵌套：li = ['alex',123,{'k1':123,'k2':{'aa':1,'bb':2}}]

列表的切片与索引

class list(object)
 |  list() -> new empty list
 |  list(iterable) -> new list initialized from iterable's items
 |  
 |  Methods defined here:
 |  
 |  __add__(self, value, /)
 |      Return self+value.
 |  
 |  __contains__(self, key, /)
 |      Return key in self.
 |  
 |  __delitem__(self, key, /)
 |      Delete self[key].
 |  
 |  __eq__(self, value, /)
 |      Return self==value.
 |  
 |  __ge__(self, value, /)
 |      Return self>=value.
 |  
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |  
 |  __getitem__(...)
 |      x.__getitem__(y) <==> x[y]
 |  
 |  __gt__(self, value, /)
 |      Return self>value.
 |  
 |  __iadd__(self, value, /)
 |      Implement self+=value.
 |  
 |  __imul__(self, value, /)
 |      Implement self*=value.
 |  
 |  __init__(self, /, *args, **kwargs)
 |      Initialize self.  See help(type(self)) for accurate signature.
 |  
 |  __iter__(self, /)
 |      Implement iter(self).
 |  
 |  __le__(self, value, /)
 |      Return self<=value.
 |  
 |  __len__(self, /)
 |      Return len(self).
 |  
 |  __lt__(self, value, /)
 |      Return self<value.
 |  
 |  __mul__(self, value, /)
 |      Return self*value.n
 |  
 |  __ne__(self, value, /)
 |      Return self!=value.
 |  
 |  __new__(*args, **kwargs) from builtins.type
 |      Create and return a new object.  See help(type) for accurate signature.
 |  
 |  __repr__(self, /)
 |      Return repr(self).
 |  
 |  __reversed__(...)
 |      L.__reversed__() -- return a reverse iterator over the list
 |  
 |  __rmul__(self, value, /)
 |      Return self*value.
 |  
 |  __setitem__(self, key, value, /)
 |      Set self[key] to value.
 |  
 |  __sizeof__(...)
 |      L.__sizeof__() -- size of L in memory, in bytes
 |  
 |  append(...)
 |      L.append(object) -> None -- append object to end
 |  
 |  clear(...)
 |      L.clear() -> None -- remove all items from L
 |  
 |  copy(...)
 |      L.copy() -> list -- a shallow copy of L
 |  
 |  count(...)
 |      L.count(value) -> integer -- return number of occurrences of value
 |  
 |  extend(...)
 |      L.extend(iterable) -> None -- extend list by appending elements from the iterable
 |  
 |  index(...)
 |      L.index(value, [start, [stop]]) -> integer -- return first index of value.
 |      Raises ValueError if the value is not present.
 |  
 |  insert(...)
 |      L.insert(index, object) -- insert object before index
 |  
 |  pop(...)
 |      L.pop([index]) -> item -- remove and return item at index (default last).
 |      Raises IndexError if list is empty or index is out of range.
 |  
 |  remove(...)
 |      L.remove(value) -> None -- remove first occurrence of value.
 |      Raises ValueError if the value is not present.
 |  
 |  reverse(...)
 |      L.reverse() -- reverse *IN PLACE*
 |  
 |  sort(...)
 |      L.sort(key=None, reverse=False) -> None -- stable sort *IN PLACE*
 |  
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |  
 |  __hash__ = None

元组(tuple)

元组的创建：

t=(1,2,3)　　创建一个元组
t=tuple([1,2,3])将列表转换为一个元组

tuple类型常用功能剖析 :
tup=（1，2，3，'a'）这就是一个元组
元组跟列表几乎是一样的
列表可以进行修改，元组不可以进行修改(不能进行增删改操作)
count()计算元素出现的次数
index()获取指定元素的索引位置

元组的嵌套

class list(object)
 |  list() -> new empty list
 |  list(iterable) -> new list initialized from iterable's items
 |  
 |  Methods defined here:
 |  
 |  __add__(self, value, /)
 |      Return self+value.
 |  
 |  __contains__(self, key, /)
 |      Return key in self.
 |  
 |  __delitem__(self, key, /)
 |      Delete self[key].
 |  
 |  __eq__(self, value, /)
 |      Return self==value.
 |  
 |  __ge__(self, value, /)
 |      Return self>=value.
 |  
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |  
 |  __getitem__(...)
 |      x.__getitem__(y) <==> x[y]
 |  
 |  __gt__(self, value, /)
 |      Return self>value.
 |  
 |  __iadd__(self, value, /)
 |      Implement self+=value.
 |  
 |  __imul__(self, value, /)
 |      Implement self*=value.
 |  
 |  __init__(self, /, *args, **kwargs)
 |      Initialize self.  See help(type(self)) for accurate signature.
 |  
 |  __iter__(self, /)
 |      Implement iter(self).
 |  
 |  __le__(self, value, /)
 |      Return self<=value.
 |  
 |  __len__(self, /)
 |      Return len(self).
 |  
 |  __lt__(self, value, /)
 |      Return self<value.
 |  
 |  __mul__(self, value, /)
 |      Return self*value.n
 |  
 |  __ne__(self, value, /)
 |      Return self!=value.
 |  
 |  __new__(*args, **kwargs) from builtins.type
 |      Create and return a new object.  See help(type) for accurate signature.
 |  
 |  __repr__(self, /)
 |      Return repr(self).
 |  
 |  __reversed__(...)
 |      L.__reversed__() -- return a reverse iterator over the list
 |  
 |  __rmul__(self, value, /)
 |      Return self*value.
 |  
 |  __setitem__(self, key, value, /)
 |      Set self[key] to value.
 |  
 |  __sizeof__(...)
 |      L.__sizeof__() -- size of L in memory, in bytes
 |  
 |  append(...)
 |      L.append(object) -> None -- append object to end
 |  
 |  clear(...)
 |      L.clear() -> None -- remove all items from L
 |  
 |  copy(...)
 |      L.copy() -> list -- a shallow copy of L
 |  
 |  count(...)
 |      L.count(value) -> integer -- return number of occurrences of value
 |  
 |  extend(...)
 |      L.extend(iterable) -> None -- extend list by appending elements from the iterable
 |  
 |  index(...)
 |      L.index(value, [start, [stop]]) -> integer -- return first index of value.
 |      Raises ValueError if the value is not present.
 |  
 |  insert(...)
 |      L.insert(index, object) -- insert object before index
 |  
 |  pop(...)
 |      L.pop([index]) -> item -- remove and return item at index (default last).
 |      Raises IndexError if list is empty or index is out of range.
 |  
 |  remove(...)
 |      L.remove(value) -> None -- remove first occurrence of value.
 |      Raises ValueError if the value is not present.
 |  
 |  reverse(...)
 |      L.reverse() -- reverse *IN PLACE*
 |  
 |  sort(...)
 |      L.sort(key=None, reverse=False) -> None -- stable sort *IN PLACE*
 |  
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |  
 |  __hash__ = None

字典(dict)

字典的创建：

a={..........}

a=dict(k1=123,k2=345)

a=dict(可迭代对象)，比如li = [1,2,3],dict(li),不可以，但是dict(enumerate(li))可以

列表元素的添加：

dic['k1']=123或者dic.update({'k1':123}),但是第一种方式更为简单

dict类型常用功能剖析:
user_info = {'sam':1,'Jim':2}这就是一个字典,大括号里面是键值对
索引：user_info['sam']
user_info.keys()获取所有的key
user_info.values()获取所有的value
user_info.items()获取所有的键值对
user_info.clear()：清除所有内容
user_info.get(key):根据key获取值，如果key不存在，可以指定一个默认值user_info.get('sas','123'),不存在的键sas，值为123
通过索引也可以获取值，但是get在key不存在的时候返回None，而索引会报错，所以推荐用get
user_info.has_key()检查字典中指定的key是否存在，python2有这个函数python3没有这个函数，用in代替：key in user_info.keys()
user_info.update()批量更新

pop()
popitem()
del user_info(key)删除键值对
循环：默认只输出key
for i in user_info:这句与for i in user_info.keys():是等价的，因为for in in user_info默认是对键进行循环。
print(i)输出key
for k,v in user_info.items():
print(k)输出key
print(v)输出value

class dict(object)
 |  dict() -> new empty dictionary
 |  dict(mapping) -> new dictionary initialized from a mapping object's
 |      (key, value) pairs
 |  dict(iterable) -> new dictionary initialized as if via:
 |      d = {}
 |      for k, v in iterable:
 |          d[k] = v
 |  dict(**kwargs) -> new dictionary initialized with the name=value pairs
 |      in the keyword argument list.  For example:  dict(one=1, two=2)
 |  
 |  Methods defined here:
 |  
 |  __contains__(self, key, /)
 |      True if D has a key k, else False.
 |  
 |  __delitem__(self, key, /)
 |      Delete self[key].
 |  
 |  __eq__(self, value, /)
 |      Return self==value.
 |  
 |  __ge__(self, value, /)
 |      Return self>=value.
 |  
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |  
 |  __getitem__(...)
 |      x.__getitem__(y) <==> x[y]
 |  
 |  __gt__(self, value, /)
 |      Return self>value.
 |  
 |  __init__(self, /, *args, **kwargs)
 |      Initialize self.  See help(type(self)) for accurate signature.
 |  
 |  __iter__(self, /)
 |      Implement iter(self).
 |  
 |  __le__(self, value, /)
 |      Return self<=value.
 |  
 |  __len__(self, /)
 |      Return len(self).
 |  
 |  __lt__(self, value, /)
 |      Return self<value.
 |  
 |  __ne__(self, value, /)
 |      Return self!=value.
 |  
 |  __new__(*args, **kwargs) from builtins.type
 |      Create and return a new object.  See help(type) for accurate signature.
 |  
 |  __repr__(self, /)
 |      Return repr(self).
 |  
 |  __setitem__(self, key, value, /)
 |      Set self[key] to value.
 |  
 |  __sizeof__(...)
 |      D.__sizeof__() -> size of D in memory, in bytes
 |  
 |  clear(...)
 |      D.clear() -> None.  Remove all items from D.
 |  
 |  copy(...)
 |      D.copy() -> a shallow copy of D
 |  
 |  fromkeys(iterable, value=None, /) from builtins.type
 |      Returns a new dict with keys from iterable and values equal to value.
 |  
 |  get(...)
 |      D.get(k[,d]) -> D[k] if k in D, else d.  d defaults to None.
 |  
 |  items(...)
 |      D.items() -> a set-like object providing a view on D's items
 |  
 |  keys(...)
 |      D.keys() -> a set-like object providing a view on D's keys
 |  
 |  pop(...)
 |      D.pop(k[,d]) -> v, remove specified key and return the corresponding value.
 |      If key is not found, d is returned if given, otherwise KeyError is raised
 |  
 |  popitem(...)
 |      D.popitem() -> (k, v), remove and return some (key, value) pair as a
 |      2-tuple; but raise KeyError if D is empty.
 |  
 |  setdefault(...)
 |      D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D
 |  
 |  update(...)
 |      D.update([E, ]**F) -> None.  Update D from dict/iterable E and F.
 |      If E is present and has a .keys() method, then does:  for k in E: D[k] = E[k]
 |      If E is present and lacks a .keys() method, then does:  for k, v in E: D[k] = v
 |      In either case, this is followed by: for k in F:  D[k] = F[k]
 |  
 |  values(...)
 |      D.values() -> an object providing a view on D's values
 |  
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |  
 |  __hash__ = None

set 　　 

set数据类型：不允许重复的无序集合，所以不能通过下标来取
创建：s = set()空集合，s= {1，2，3，4}
转换：s = set([1,2,3，3])把可迭代对象里面相同的元素都去掉

set的方法：
add() 添加一个元素
clear()将集合清空
difference() ret = se.difference(be)，找se中存在，be中不存在的元素，并给新的集合
difference_update 找se中存在，be中不存在的元素，并给新的集合，更新自己
discard()移除指定元素，不存在不报错
remove()移除指定元素，不存在会报错
set1.intersection(set2)交集，并给一个新的集合
set1.intersection_update(set2)交集，并更新自己
set1.isdisjoint(set2),有交集False,没交集True
set1.issubset(set2) set1是不是set2的子序列
set1.issuperset(set2) set1是不是set2的父序列
pop()与remove区别,pop可以拿到返回值（也就是移除的那个元素），remove拿不到

 一般来说，字符串执行一个功能，会产生一个新的，原来的不变，列表、元组、字典执行一个功能，一般会自身发生变化

还有一点，在类的源码定义中，

　　　　　　　　　　　　　　如果没有staticmethod,调用方式为：

　　　　　　　　　　　　　　　　　　　　　　　　　　　　对象.方法；

　　　　　　　　　　　　　　如果有staticmethod,调用方式为：

　　　　　　　　　　　　　　　　　　　　　　　　　　　　类.方法