Python – 过滤所有偶数元素的元组

给定元组列表，仅过滤具有所有偶数元素的元组。

Input : test_list = [(6, 4, 2, 8), (5, 6, 7, 6), (8, 1, 2), (7, )]
Output : [(6, 4, 2, 8)]
Explanation : Only 1 tuple with all even elements.

Input : test_list = [(6, 4, 2, 9), (5, 6, 7, 6), (8, 1, 2), (7, )]
Output : []
Explanation : No tuple with all even elements.

方法#1：使用循环

在此，我们迭代每个元组，并使用 %运算符检查所有偶数元素，如果偶数元素是奇数，则元组被标记并且不添加到结果列表中。

Python3

# Python3 code to demonstrate working of 
# Filter Tuples with All Even Elements
# Using loop
  
# initializing list
test_list = [(6, 4, 2, 8), (5, 6, 7, 6), (8, 0, 2), (7, )]
  
# printing original list
print("The original list is : " + str(test_list))
  
res_list = []
for sub in test_list:
    res = True 
      
    # check if all are even
    for ele in sub:
        if ele % 2 != 0:
            res = False
            break
    if res:
        res_list.append(sub)
  
# printing results
print("Filtered Tuples : " + str(res_list))

输出

The original list is : [(6, 4, 2, 8), (5, 6, 7, 6), (8, 0, 2), (7, )]
Filtered Tuples : [(6, 4, 2, 8), (8, 0, 2)]

方法 #2：使用 all() + 列表推导

在此，检查所有元素是否为偶数的任务是使用 all() 完成的，列表推导式用于过滤后检查的任务。

Python3

# Python3 code to demonstrate working of 
# Filter Tuples with All Even Elements
# Using all() + list comprehension
  
# initializing list
test_list = [(6, 4, 2, 8), (5, 6, 7, 6), (8, 0, 2), (7, )]
  
# printing original list
print("The original list is : " + str(test_list))
  
# testing for tuple to be even using all()
res = [sub for sub in test_list if all(ele % 2 == 0 for ele in sub)]
  
# printing results
print("Filtered Tuples : " + str(res))

输出

The original list is : [(6, 4, 2, 8), (5, 6, 7, 6), (8, 0, 2), (7, )]
Filtered Tuples : [(6, 4, 2, 8), (8, 0, 2)]