从Python列表中删除所有出现的元素

任务是执行删除列表中存在的给定项目/元素的所有出现的操作。例子 ：

Input : 1 1 2 3 4 5 1 2 1 Output : 2 3 4 5 2 Explanation : The input list is [1, 1, 2, 3, 4, 5, 1, 2] and the item to be removed is 1. After removing the item, the output list is [2, 3, 4, 5, 2] Input : 5 6 7 8 9 10 7 Output : 5 6 8 9 10

在本文中，我们将了解如何以 3 种方式执行此任务：

1. 使用列表理解
2. 使用 filter() 和 __ne__
3. 使用删除（）

方法 1：使用列表推导 列表推导可用于执行此任务，我们只需检查匹配项并在没有目标元素的情况下重建列表。我们可以在满足特定条件的列表中创建这些元素的子列表。

Python3

# Python 3 code to demonstrate
# the removal of all occurrences of a
# given item using list comprehension
 
def remove_items(test_list, item):
     
    # using list comprehension to perform the task
    res = [i for i in test_list if i != item]
 
    return res
 
# driver code
if __name__=="__main__":
     
    # initializing the list
    test_list = [1, 3, 4, 6, 5, 1]
 
    # the item which is to be removed
    item = 1
 
    # printing the original list
    print ("The original list is : " + str(test_list))
 
    # calling the function remove_items()
    res = remove_items(test_list, item)
 
    # printing result
    print ("The list after performing the remove operation is : " + str(res))

输出

The original list is : [1, 3, 4, 6, 5, 1]
The list after performing the remove operation is : [3, 4, 6, 5]

方法 2：使用 filter() 和 __ne__ 我们过滤列表中不等于 __ne__ 的项目。

Python3

# Python 3 code to demonstrate
# the removal of all occurrences of
# a given item using filter() and __ne__
 
def remove_items(test_list, item):
     
    # using filter() + __ne__ to perform the task
    res = list(filter((item).__ne__, test_list))
 
    return res
 
# driver code
if __name__=="__main__":
     
    # initializing the list
    test_list = [1, 3, 4, 6, 5, 1]
 
    # the item which is to be removed
    item = 1
 
    # printing the original list
    print ("The original list is : " + str(test_list))
 
    # calling the function remove_items()
    res = remove_items(test_list, item)
 
    # printing result
    print ("The list after performing the remove operation is : " + str(res))

输出

The original list is : [1, 3, 4, 6, 5, 1]
The list after performing the remove operation is : [3, 4, 6, 5]

方法3：使用remove() 在这个方法中，我们遍历列表中的每一项，当我们找到要移除的项的匹配项时，我们会调用列表的remove()函数。

Python3

# Python 3 code to demonstrate
# the removal of all occurrences of
# a given item using remove()
 
def remove_items(test_list, item):
     
    # remove the item for all its occurrences
    c = test_list.count(item)
    for i in range(c):
            test_list.remove(item)
 
    return test_list
 
# driver code
if __name__=="__main__":
     
    # initializing the list
    test_list = [1, 3, 4, 6, 5, 1]
 
    # the item which is to be removed
    item = 1
 
    # printing the original list
    print ("The original list is :" + str(test_list))
 
    # calling the function remove_items()
    res = remove_items(test_list, item)
 
    # printing result
    print ("The list after performing the remove operation is :" + str(res))

输出

The original list is : [1, 3, 4, 6, 5, 1]
The list after performing the remove operation is : [3, 4, 6, 5]