6.序列！序列！

列表/元组/字符串的共同点：- 都可以通过索引得到每一个元素- 默认索引从0开始- 切片方法得到一个范围内的元素的集合- 有很多共同的操作符（重复操作符/拼接操作符/成员关系操作符）

list()：把可迭代对象转换为列表

help(list)见下：class list(object) |  list() -> new empty list |  list(iterable) -> new list initialized from iterable's items |   |  Methods defined here: |   |  __add__(...) |      x.__add__(y) <==> x+y |   |  __contains__(...) |      x.__contains__(y) <==> y in x |   |  __delitem__(...) |      x.__delitem__(y) <==> del x[y] |   |  __delslice__(...) |      x.__delslice__(i, j) <==> del x[i:j] |       |      Use of negative indices is not supported. |   |  __eq__(...)【例】>>> a = list()>>> a[]>>> >>> b = 'I love fishC'>>> b = list(b)>>> b['I', ' ', 'l', 'o', 'v', 'e', ' ', 'f', 'i', 's', 'h', 'C']>>> 

tuple：把可迭代对象转换成元组

help(tuple)见下：class tuple(object) |  tuple() -> empty tuple |  tuple(iterable) -> tuple initialized from iterable's items |   |  If the argument is a tuple, the return value is the same object. |   |  Methods defined here: |   |  __add__(...) |      x.__add__(y) <==> x+y |   |  __contains__(...) |      x.__contains__(y) <==> y in x |   |  __eq__(...) |      x.__eq__(y) <==> x==y |   |  __ge__(...) |      x.__ge__(y) <==> x>=y |   |  __getattribute__(...)【例】>>> a = tuple()>>> a()>>> >>> b = 'I love fishC'>>> b = tuple(b)>>> b('I', ' ', 'l', 'o', 'v', 'e', ' ', 'f', 'i', 's', 'h', 'C')>>> 

str：把参数转换成字符串

help(str)见下：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. |   |  Method resolution order: |      str |      basestring |      object |   |  Methods defined here: |   |  __add__(...) |      x.__add__(y) <==> x+y |   |  __contains__(...) |      x.__contains__(y) <==> y in x |   |  __eq__(...) |      x.__eq__(y) <==> x==y【例】>>> a = 'I love fishC'>>> str(a)'I love fishC'>>> >>> len(a)   #长度12>>> max(a)  #返回序列或参数集合中的最大值'v'>>> max(1,1,2,-3,4)   #min()最小值4>>> tuple = (1,2,3,4,5)>>> max(tuple)5>>> min(tuple)1注解：使用max/min，必须保证数据类型一致>>> t1 = (1,2,3,4)>>> sum(t1)  #求总和10>>> sorted(t1)   #排序[1, 2, 3, 4]reversed  #反转>>> reversed(t1)<reversed object at 0x7f1c2cb10690>  #返回的是一个迭代器对象>>> list(reversed(t1))  #把迭代器对象转换成list[4, 3, 2, 1]enumerate  >>> enumerate(t1)<enumerate object at 0x7f1c2cb54aa0> #返回的是一个迭代器对象>>> list(enumerate(t1))[(0, 1), (1, 2), (2, 3), (3, 4)] #把迭代器对象转换成listzip >>> t1 = (1,2)>>> t2 = (4,5,6,7,8)>>> zip(t1,t2)[(1, 4), (2, 5)]