my_tuple = [(14, 15, 19), (-32, 23, 32), (-31, 15, 63), (46, 68)]

print("列表是：")
print(my_tuple)

my_result = [sub for sub in my_tuple if all(element >= 0 for element in sub)]

print("结果是：")
print(my_result)

The list is :
[(14, 15, 19), (-32, 23, 32), (-31, 15, 63), (46, 68)]
The result is :
[(14, 15, 19), (46, 68)]