Partial itertools.product in python-CodePudding

I would like to create the following list of tuples in Python, based on a list of possible values [0, 1, 2, 3]:

(0, 0,  0),  # all set to first value: 0
(0, 0,  1),
(0, 0,  2),
(0, 0,  3),
(0, 1,  0),
(0, 2,  0),
(0, 3,  0),
(1, 0,  0),
(2, 0,  0),
(3, 0,  0),
(3, 3,  3),   # all set to last value: 3

To summarize:

first value (0) for all elements of the tuples
each value of the list of values ([0, 1, 2, 3]) for a given element of the tuple and other elements set to 0
last value (3) for all elements of the tuples

What would be an efficient way to do it? ... maybe there is a magic function to do it?

I was first thinking of using itertools.product and then filtering:

list(product([0, 1, 2, 3], repeat=3))

... or maybe by using pandas (which looks a bit overkill though).

Thanks

CodePudding user response：

I found a super ugly way, that might need to be optimized (but at least it's working):

[
 t for t in product(range(4), repeat=3)
 if all(e==0 for e in t) or all(e==3 for e in t) or sum([e!=0 for e in t])==1
]

Don't hesitate if you have a better way.

CodePudding user response：

You can make this list comprehension

for x in [ (a,b,c) 
    for a in range(4) 
    for b in range(4) 
    for c in range(4) 
    if a b   == 0 
    or b c   == 0 
    or a c   == 0 
    or a b c == 9
]: print(x)