列表列表：添加每个列表中的所有项目

Question

I want to write an if-statement for this list:

x = int(input())
y = int(input())
z = int(input())
n = int(input())

lst= ([[a, b, c] for a in range(0,x+1) for b in range(0,y+1) for c in range(0,z+1)])`

I want to add a, b and c in all lists and if they are not equal to n, print each of them. How should I do that?

Answer 1

you can use an if condition in list comprehension, which makes this easy to achieve

lst= ([[a, b, c] for a in range(0,x+1) for b in range(0,y+1) for c in range(0,z+1) if a+b+c != n])

Answer 2

lst = []

for a in range(0, x + 1):
  if a != n:
    print(a)
    lst.append(a)

for b in range(0, y + 1):
  if b != n:
    print(b)
    lst.append(b)


for c in range(0, z + 1):
  if c != n:
    print(c)
    lst.append(c)

You can use if statement inside list comprehension but not in this context because you will need an else statement

Answer 3

A filter & itertools approach:

> a, b, c, n = 1, 1, 1, 2
> all_combos = itertools.product(range(a+1), range(b+1), range(c+1))
> lst = list(filter(lambda x: sum(x) != n, all_combos))
> print(lst)
[(0, 0, 0), (0, 0, 1), (0, 1, 0), (1, 0, 0), (1, 1, 1)]