Python list

一、创建一个列表

用把逗号分隔的不同的数据项使用方括号括起来即可。如下所示：

>>> name_list = ["root", "gm", "hlr"]

  

二、访问列表中的值

使用下标索引来访问列表中的值，与字符串的索引一样，列表索引从0开始。列表可以进行截取、组合等。

>>> name_list
['root', 'gm', 'hlr']

三、查看列表可进行的操作

>>> help(name_list)
·················
>>> dir(name_list)
['append', 'clear', 'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']

　　append("STRING")：向列表的末尾追加一个新的值

　　clear：

　　copy：

　　count("STRING")：统计某字符串或值在列表中出现的次数

　　extend：

　　index("STRING")：某值在列表中第一次出现的位置

　　insert(Ｎ,"STRING")：向列表的位置Ｎ处插入一个新值

　　pop(obj=list[-1])：删除列表某个位置的值，默认为最后一个值

　　remove("STRING")：移除列表中某个值的第一个匹配项

　　reverse()：列表元素值反序排列 　　
　　
　　sort()：对列表内的所以值按照ASCII码进行排序

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) -- append object to end """
        pass

    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) -- 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) -- 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, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__
        """
        L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;
        cmp(x, y) -> -1, 0, 1
        """
        pass

    def __add__(self, y): # real signature unknown; restored from __doc__
        """ x.__add__(y) <==> x+y """
        pass

    def __contains__(self, y): # real signature unknown; restored from __doc__
        """ x.__contains__(y) <==> y in x """
        pass

    def __delitem__(self, y): # real signature unknown; restored from __doc__
        """ x.__delitem__(y) <==> del x[y] """
        pass

    def __delslice__(self, i, j): # real signature unknown; restored from __doc__
        """
        x.__delslice__(i, j) <==> del x[i:j]
                   
                   Use of negative indices is not supported.
        """
        pass

    def __eq__(self, y): # real signature unknown; restored from __doc__
        """ x.__eq__(y) <==> x==y """
        pass

    def __getattribute__(self, name): # real signature unknown; restored from __doc__
        """ x.__getattribute__('name') <==> x.name """
        pass

    def __getitem__(self, y): # real signature unknown; restored from __doc__
        """ x.__getitem__(y) <==> x[y] """
        pass

    def __getslice__(self, i, j): # real signature unknown; restored from __doc__
        """
        x.__getslice__(i, j) <==> x[i:j]
                   
                   Use of negative indices is not supported.
        """
        pass

    def __ge__(self, y): # real signature unknown; restored from __doc__
        """ x.__ge__(y) <==> x>=y """
        pass

    def __gt__(self, y): # real signature unknown; restored from __doc__
        """ x.__gt__(y) <==> x>y """
        pass

    def __iadd__(self, y): # real signature unknown; restored from __doc__
        """ x.__iadd__(y) <==> x+=y """
        pass

    def __imul__(self, y): # real signature unknown; restored from __doc__
        """ x.__imul__(y) <==> x*=y """
        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): # real signature unknown; restored from __doc__
        """ x.__iter__() <==> iter(x) """
        pass

    def __len__(self): # real signature unknown; restored from __doc__
        """ x.__len__() <==> len(x) """
        pass

    def __le__(self, y): # real signature unknown; restored from __doc__
        """ x.__le__(y) <==> x<=y """
        pass

    def __lt__(self, y): # real signature unknown; restored from __doc__
        """ x.__lt__(y) <==> x<y """
        pass

    def __mul__(self, n): # real signature unknown; restored from __doc__
        """ x.__mul__(n) <==> x*n """
        pass

    @staticmethod # known case of __new__
    def __new__(S, *more): # real signature unknown; restored from __doc__
        """ T.__new__(S, ...) -> a new object with type S, a subtype of T """
        pass

    def __ne__(self, y): # real signature unknown; restored from __doc__
        """ x.__ne__(y) <==> x!=y """
        pass

    def __repr__(self): # real signature unknown; restored from __doc__
        """ x.__repr__() <==> repr(x) """
        pass

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

    def __rmul__(self, n): # real signature unknown; restored from __doc__
        """ x.__rmul__(n) <==> n*x """
        pass

    def __setitem__(self, i, y): # real signature unknown; restored from __doc__
        """ x.__setitem__(i, y) <==> x[i]=y """
        pass

    def __setslice__(self, i, j, y): # real signature unknown; restored from __doc__
        """
        x.__setslice__(i, j, y) <==> x[i:j]=y
                   
                   Use  of negative indices is not supported.
        """
        pass

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

    __hash__ = None

四、append

# 原列表

>>> name_list
['root', 'gm', 'hlr']

# 新增一个root值

>>> name_list.append("root")

# 新列表

>>> name_list
['root', 'gm', 'hlr', 'root']

五、count

# 统计root用户在列表中出现的次数

>>> name_list.count("root")
2

# 额外补充，如何删除列表中的root值(此时列表有２个值为root)

>>> name_list
['root', 'hlr', 'gm', 'root']
>>> for i in range(name_list.count("root")):
... name_list.remove("root")
... 
>>> name_list
['hlr', 'gm']

六、index

# 原列表

>>> name_list
['root', 'gm', 'hlr', 'root']

# 查看hlr用户在列表第一次出现的位置

>>> name_list.index("hlr")
2

  

七、insert

# 原列表

>>> name_list

['root', 'gm', 'hlr', 'root']

# 在列表的位置２处新增一个test用户

>>> name_list.insert(2, "test")

# 新列表

>>> name_list
['root', 'gm', 'test', 'hlr', 'root']

 

八、pop

# 原列表

>>> name_list
['root', 'gm', 'test', 'hlr', 'root']

# 删除列表位置为２的值

>>> name_list.pop(2)
'test'

# 新列表
>>> name_list
['root', 'gm', 'hlr', 'root']

# 删除列表最后一个值

>>> name_list.pop()
'root'

# 新列表
>>> name_list
['root', 'gm', 'hlr']

九、remove

# 原列表

>>> name_list
['root', 'gm', 'hlr']

# 新增一个gm用户

>>> name_list.append("gm")

# 新列表

>>> name_list
['root', 'gm', 'hlr', 'gm']

# 移除第一个gm用户

>>> name_list.remove("gm")

# 新列表
>>> name_list
['root', 'hlr', 'gm']

十、reverse

# 原列表
>>> name_list
['root', 'hlr', 'gm']

# 反向排列列表中元素

>>> name_list.reverse()

# 新列表

>>> name_list
['gm', 'hlr', 'root']

 

十一、sort

# 原列表

>>> name_list
['root', 'hlr', 'gm']

# 对列表进行排序

>>> name_list.sort()

# 新列表
>>> name_list
['gm', 'hlr', 'root']

更多列表操作

 https://www.cnblogs.com/python-gm/p/12395591.html