python: append & extend 异同

  经过试验，总结出 python 中 append 和 extend 的异同点如下表：

Func Same Point Difference append 只能作用于 list 型数据，每次只能输入 单 参数 只能以 单元素 的形式被 添加到 list 尾部，list层级数加1 extend 同上 只能以 list 的形式被 连接到 list 尾部，不改变list层级数

  代码示例０：

list = ('Hello', 1, '@')list

('Hello', 1, '@')

 list.append('#')

Traceback (most recent call last):  File "<stdin>", line 1, in <module>AttributeError: 'tuple' object has no attribute 'append'

list.extend('#')

Traceback (most recent call last):  File "<stdin>", line 1, in <module>AttributeError: 'tuple' object has no attribute 'extend'

  AttributeError: ‘tuple’ object has no attribute ‘append’、 ‘extend’：说明append、 extend只能作用于 list 型数据。


  代码示例１：

list = ['Hello', 1, '@']list.append(2)list

['Hello', 1, '@', 2, 3]

list = ['Hello', 1, '@', 2]list.append((3, 4))list

['Hello', 1, '@', 2, (3, 4)]

list.append([3, 4])list

['Hello', 1, '@', 2, (3, 4), [3, 4]]

list.append(3, 4)

Traceback (most recent call last):  File "<stdin>", line 1, in <module>TypeError: append() takes exactly one argument (2 given)

list.extend([5, 6])list

['Hello', 1, '@', 2, (3, 4), [3, 4], 5, 6]

list.extend((5, 6))list

['Hello', 1, '@', 2, (3, 4), [3, 4], 5, 6, 5, 6]

list.extend(5, 6)

Traceback (most recent call last):  File "<stdin>", line 1, in <module>TypeError: extend() takes exactly one argument (2 given)

  TypeError: append() takes exactly one argument、TypeError: extend() takes exactly one argument：说明append、 extend每次只能输入单参数。

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