list和dict的应用

1. list列表扩展的方式有几种(或者说添加元素的方法)

extend:通过迭代追加来扩展元素

insert:在索引前插入对象

 

append:追加到末尾

 

2. 对["cherry", "litchi", "strawberry", "mangosteen", "pomelo", "pineapple", "pitaya", "durian"]进行默认排序和使用第三个字母进行排序 

 

 3. dict中所有方法的使用(先写源代码再写样例)

clear(self): # real signature unknown; restored from __doc__

    """ D.clear() -> None.  Remove all items from D. """

                       删除所有项目

 

opy(self): # real signature unknown; restored from __doc__

    """ D.copy() -> a shallow copy of D """

                     浅拷贝 

 

get(self, *args, **kwargs): # real signature unknown

    """ Return the value for key if key is in the dictionary, else default. """

            如果 key 在字典中，则返回 key 的值，否则返回默认值

 

 

items(self): # real signature unknown; restored from __doc__

    """ D.items() -> a set-like object providing a view on D's items "

                 一个类似集合的对象，提供字典项目的视图

 

keys(self): # real signature unknown; restored from __doc__

    """ D.keys() -> a set-like object providing a view on D's keys ""

                 一个类似集合的对象，提供 字典键上的视图

 

 

pop(self, k, d=None): # real signature unknown; restored from __doc__

    """

    D.pop(k[,d]) -> v, remove specified key and return the corresponding value.

             删除指定的键并返回相应的值

 

 

If key is not found, default is returned if given, otherwise KeyError is raised

如果未找到 key，则返回 default（如果给定），否则引发 KeyError

 

 

popitem(self, *args, **kwargs): # real signature unknown

    """

    Remove and return a (key, value) pair as a 2-tuple.

          删除（键、值）对并将其作为 二元组返回。

 

Pairs are returned in LIFO (last-in, first-out) order.

     成对按后进先出（后进先出）顺序返回

    Raises KeyError if the dict is empty.

                   如果字典为空，则引发 KeyErro

 

 

setdefault(self, *args, **kwargs): # real signature unknown

    """

    Insert key with a value of default if key is not in the dictionary.

        如果键不在字典中，则插入值为默认值的键。

 

 

Return the value for key if key is in the dictionary, else default.

    """如果 key 在字典中，则返回 key 的值，否则返回默认值。

 

update(self, E=None, **F): # known special case of dict.update

    """

    D.update([E, ]**F) -> None.  Update D from dict/iterable E and F.

     从字典/可迭代 E 和 F 更新 D

If E is present and has a .keys() method, then does:  for k in E: D[k] = E[k]

如果 E 存在并且具有 .keys（） 方法，则对于 E 中的 k：D[k] = E[k]

    If E is present and lacks a .keys() method, then does:  for k, v in E: D[k] = v

如果 E 存在并且缺少 .keys（） 方法，则对于 E 中的 k， v：D[k] = v

    In either case, this is followed by: for k in F:  D[k] = F[k]

        在任何一种情况下，这后面跟着：对于F中的k：D[k] = F[k]

values(self): # real signature unknown; restored from __doc__

    """ D.values() -> an object providing a view on D's values """

            在任何一种情况下，这后面跟着：对于F中的k：D[k] = F[k]