一.基本数据类型
整数:int
字符串:str(注:\\t等于一个tab键)
布尔值: bool
列表:list
列表用[]
元祖:tuple
元祖用()
字典:dict
注:所有的数据类型都存在想对应的类列里,元祖和列表功能一样,列表可以修改,元祖不能修改。
二.列表所有数据类型:
基本操作:
索引,切片,长度,包含,循环
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. \"\"\" def count(self, value): # real signature unknown; restored from __doc__ \"\"\" T.count(value) -> integer -- return number of occurrences of value \"\"\" (T.count(价值)- >整数,返回值的出现次数) return 0 def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__ \"\"\" T.index(value, [start, [stop]]) -> integer -- return first index of value. Raises ValueError if the value is not present. \"\"\" (T。指数(价值,[开始,[不要]])- >整数,返回第一索引值。提出了ValueError如果不存在的价值。) return 0 def __add__(self, *args, **kwargs): # real signature unknown \"\"\" Return self+value. \"\"\" pass def __contains__(self, *args, **kwargs): # real signature unknown \"\"\" Return key in self. \"\"\" pass def __eq__(self, *args, **kwargs): # real signature unknown \"\"\" Return self==value. \"\"\" pass def __getattribute__(self, *args, **kwargs): # real signature unknown \"\"\" Return getattr(self, name). \"\"\" pass def __getitem__(self, *args, **kwargs): # real signature unknown \"\"\" Return self[key]. \"\"\" pass def __getnewargs__(self, *args, **kwargs): # real signature unknown pass def __ge__(self, *args, **kwargs): # real signature unknown \"\"\" Return self>=value. \"\"\" pass def __gt__(self, *args, **kwargs): # real signature unknown \"\"\" Return self>value. \"\"\" pass def __hash__(self, *args, **kwargs): # real signature unknown \"\"\" Return hash(self). \"\"\" pass def __init__(self, seq=()): # known special case of tuple.__init__ \"\"\" tuple() -> empty tuple tuple(iterable) -> tuple initialized from iterable\'s items If the argument is a tuple, the return value is the same object. # (copied from class doc) \"\"\" pass def __iter__(self, *args, **kwargs): # real signature unknown \"\"\" Implement iter(self). \"\"\" pass def __len__(self, *args, **kwargs): # real signature unknown \"\"\" Return len(self). \"\"\" pass def __le__(self, *args, **kwargs): # real signature unknown \"\"\" Return self<=value. \"\"\" pass def __lt__(self, *args, **kwargs): # real signature unknown \"\"\" Return self三.所有元祖数据类型举例
#count 用于计算元素出现的个数 name_tuple = (\"zhangyanlin\",\"suoning\",\"nick\") print(name_tuple.count(\'zhangyanlin\')) #index获取指定元素的指定位置 name_tuple = (\"zhangyanlin\",\"suoning\",\"nick\") print(name_tuple.index(\'zhangyanlin\'))四.索引
name_tuple = (\"zhangyanlin\",\"suoning\",\"nick\") print(name_tuple[1])五.切片
#取出第一位到最后一位减1的元素 name_tuple = (\"zhangyanlin\",\"suoning\",\"nick\") print(name_tuple[0:len(name_tuple)-1])六.总长度len
#取出最后一位减1的元素 name_tuple = (\"zhangyanlin\",\"suoning\",\"nick\") print(name_tuple[len(name_tuple)-1])七.for循环
name_tuple = (\"zhangyanlin\",\"suoning\",\"nick\") for i in name_tuple: print(i)那么使用 tuple 有什么好处呢?
Tuple 比 list 操作速度快。如果您定义了一个值的常量集,并且唯一要用它做的是不断地遍历它,请使用 tuple 代替 list。
如果对不需要修改的数据进行 “写保护”,可以使代码更安全。使用 tuple 而不是 list 如同拥有一个隐含的 assert 语句,说明这一数据是常量。如果必须要改变这些值,则需要执行 tuple 到 list 的转换 (需要使用一个特殊的函数)。还记得我说过 dictionary keys 可以是字符串,整数和 “其它几种类型”吗?Tuples 就是这些类型之一。Tuples 可以在 dictionary 中被用做 key,但是 list 不行。实际上,事情要比这更复杂。Dictionary key 必须是不可变的。Tuple 本身是不可改变的,但是如果您有一个 list 的 tuple,那就认为是可变的了,用做 dictionary key 就是不安全的。只有字符串、整数或其它对 dictionary 安全的 tuple 才可以用作 dictionary key。
Tuples 可以用在字符串格式化中,我们会很快看到。