python删除list中元素的三种方法
- a.pop(index):删除列表a中index处的值,并且返回这个值.
- del(a[index]):删除列表a中index处的值,无返回值. del中的index可以是切片,所以可以实现批量删除.
- a.remove(value):删除列表a中第一个等于value的值,无返回.
>>> a = [0, 2, 3, 2] >>> a.remove(2) >>> a [0, 3, 2] >>> a = [3, 2, 2, 1] >>> del a[1] >>> a [3, 2, 1] >>> a = [4, 3, 5] >>> a.pop(1) 3 >>> a [4, 5] #错误信息也不一样 >>> a = [4, 5, 6] >>> a.remove(7) Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: list.remove(x): x not in list >>> del a[7] Traceback (most recent call last): File "<stdin>", line 1, in <module> IndexError: list assignment index out of range >>> a.pop(7) Traceback (most recent call last): File "<stdin>", line 1, in <module> IndexError: pop index out of range