Python基础（5）：基本数据类型（list）

列表（list）：

　　说明：列表是最常用的Python数据类型，它可以作为一个方括号内的逗号分隔值出现。列表的数据项不需要具有相同的类型。创建一个列表，只要把逗号分隔的不同的数据项使用方括号括起来即可。

　　示例：

　　　　name_list1 = ['physics', 'chemistry', 1997, 2000]

　　　　name_list2 = [1, 2, 3, 4, 5 ]

　　　　name_list3 = ["a", "b", "c", "d"]

基本操作：

• 索引
• 切片
• 追加
• 删除
• 长度
• 切片
• 循环
• 包含

class list(object):
    """
    list() -> new empty list
    list(iterable) -> new list initialized from iterable's items
    """
    def append(self, p_object): # real signature unknown; restored from __doc__
        """ L.append(object) -> None -- append object to end """
        pass

    def clear(self): # real signature unknown; restored from __doc__
        """ L.clear() -> None -- remove all items from L """
        pass

    def copy(self): # real signature unknown; restored from __doc__
        """ L.copy() -> list -- a shallow copy of L """
        return []

    def count(self, value): # real signature unknown; restored from __doc__
        """ L.count(value) -> integer -- return number of occurrences of value """
        return 0

    def extend(self, iterable): # real signature unknown; restored from __doc__
        """ L.extend(iterable) -> None -- extend list by appending elements from the iterable """
        pass

    def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
        """
        L.index(value, [start, [stop]]) -> integer -- return first index of value.
        Raises ValueError if the value is not present.
        """
        return 0

    def insert(self, index, p_object): # real signature unknown; restored from __doc__
        """ L.insert(index, object) -- insert object before index """
        pass

    def pop(self, index=None): # real signature unknown; restored from __doc__
        """
        L.pop([index]) -> item -- remove and return item at index (default last).
        Raises IndexError if list is empty or index is out of range.
        """
        pass

    def remove(self, value): # real signature unknown; restored from __doc__
        """
        L.remove(value) -> None -- remove first occurrence of value.
        Raises ValueError if the value is not present.
        """
        pass

    def reverse(self): # real signature unknown; restored from __doc__
        """ L.reverse() -- reverse *IN PLACE* """
        pass

    def sort(self, key=None, reverse=False): # real signature unknown; restored from __doc__
        """ L.sort(key=None, reverse=False) -> None -- stable sort *IN PLACE* """
        pass

    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 __delitem__(self, *args, **kwargs): # real signature unknown
        """ Delete self[key]. """
        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, y): # real signature unknown; restored from __doc__
        """ x.__getitem__(y) <==> x[y] """
        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 __iadd__(self, *args, **kwargs): # real signature unknown
        """ Implement self+=value. """
        pass

    def __imul__(self, *args, **kwargs): # real signature unknown
        """ Implement self*=value. """
        pass

    def __init__(self, seq=()): # known special case of list.__init__
        """
        list() -> new empty list
        list(iterable) -> new list initialized from iterable's items
        # (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<value. """
        pass

    def __mul__(self, *args, **kwargs): # real signature unknown
        """ Return self*value.n """
        pass

    @staticmethod # known case of __new__
    def __new__(*args, **kwargs): # real signature unknown
        """ Create and return a new object.  See help(type) for accurate signature. """
        pass

    def __ne__(self, *args, **kwargs): # real signature unknown
        """ Return self!=value. """
        pass

    def __repr__(self, *args, **kwargs): # real signature unknown
        """ Return repr(self). """
        pass

    def __reversed__(self): # real signature unknown; restored from __doc__
        """ L.__reversed__() -- return a reverse iterator over the list """
        pass

    def __rmul__(self, *args, **kwargs): # real signature unknown
        """ Return self*value. """
        pass

    def __setitem__(self, *args, **kwargs): # real signature unknown
        """ Set self[key] to value. """
        pass

    def __sizeof__(self): # real signature unknown; restored from __doc__
        """ L.__sizeof__() -- size of L in memory, in bytes """
        pass

    __hash__ = None

常用功能：

索引示例：

name_list = ['one','two','three']
print(name_list[0])
print(name_list[1])
print(name_list[2])

运行结果：
one
two
three

 

索引删除示例：

name_list = ['one','two','three']
del name_list[1]
print(name_list)

运行结果：
['one', 'three']

 

切片示例：

name_list = ['one','two','three']
print(name_list[0:2])
print(name_list[2:len(name_list)])

运行结果：
['one', 'two']
['three']

 

切片删除示例：

name_list = ['one','two','three']
del name_list[1:3]
print(name_list)

运行结果：
['one']

 

for循环示例：

name_list = ['one','two','three']
for i in name_list:
    print(i)

运行结果：
one
two
three

 

列表内部提供的其他功能：

append(self, p_object)：

　　说明：用于在列表末尾添加新的对象。p_object：追加的对象。（返回None）

　　示例：

name_list1= ['one','two','three']
name_list2= ['one','two','three']
name_list3= ['one','two','three']
name_list1.append('four')
name_list2.append(['1','2','3'])
name_list3.append(4)
print(name_list1)
print(name_list2)
print(name_list3)

运行结果：
['one', 'two', 'three', 'four']
['one', 'two', 'three', ['1', '2', '3']]
['one', 'two', 'three', 4]

• 列表可包含任何数据类型的元素，单个列表中的元素无须全为同一类型。
• 只向列表的尾部添加一个新的元素。

 

count(self,value)：

　　说明：统计列表中某个对象出现的次数。value：要统计的对象。（返回int）

　　示例：

name_list1= ['one','two','three']
name_list1.append('four')
name_list1.append('four')
name_list1.append('four')
print(name_list1)
print(name_list1.count('four'))

运行结果：
['one', 'two', 'three', 'four', 'four', 'four']
3

 

extend(self, iterable)：

　　说明：在列表末尾一次性追加另一个序列中的多个值（用新列表扩展原来的列表）。iterable（可迭代的）：扩展的对象（返回None）

　　示例：

aList = [123, 'xyz', 'zara', 'abc', 123]
bList = [2009, 'manni']
aList.extend(bList)

print ("Extended List : ", aList)

运行结果：
Extended List :  [123, 'xyz', 'zara', 'abc', 123, 2009, 'manni']

 

index(self, value, start=None, end=None)：

　　说明：从列表中找出某个值第一个匹配项的索引位置。value：查找匹配项。start：开始位置（从0开始），默认为无。end：结束位置，默认为无。（返回int）

　　示例：

aList = [123, 'xyz', 'zara', 'abc', 123]
print(aList.index(123))

运行结果：
0

 

insert(self, index, p_object)：

　　说明：用于将指定对象插入列表的指定位置。index：位置。p_object：插入的对象。

　　示例：

aList = [123, 'xyz', 'zara', 'abc', 123]
aList.insert(1,'SB')
print(aList)

运行结果：
[123, 'SB', 'xyz', 'zara', 'abc', 123]

 

pop(self, index=None)：

　　说明：移除列表中的一个元素（默认最后一个元素），并且返回该元素的值。index：移除元素的位置，默认为无。（返回移除的元素的值）

　　示例：

aList = [123, 'xyz', 'zara', 'abc', 123]
aList.pop(2)
print(aList)

运行结果：
[123, 'xyz', 'abc', 123]

 

remove(self, value)：

　　说明：移除列表中某个值的第一个匹配项。value：移除的第一个匹配元素。（返回None）

 　　示例：

aList = [123, 'xyz', 'zara', 'abc', 123]
aList.remove('xyz')
print(aList)

运行结果：
[123, 'zara', 'abc', 123]

 

reverse(self)：

　　说明：反向列表中元素。

　　示例：

aList = [123, 'xyz', 'zara', 'abc', 567]
aList.reverse()
print(aList)

运行结果：
[567, 'abc', 'zara', 'xyz', 123]

 

sort(self, key=None, reverse=Flase)：

　　说明：对原列表进行排序，如果指定参数，则使用比较函数指定的比较函数。

　　示例：

aList = [ 'xyz', 'zara', 'abc', 'xyz']
aList.sort()
print ("List : ", aList)

运行结果：
List :  ['abc', 'xyz', 'xyz', 'zara']