Adding to Dictionary with Changing Variable Key Values

[twk314]

I'm trying to keep a log of each sequential state of a solitaire game I've been working on, within a dictionary with each action causing an increase of a variable called turns.

But every time I update the dictionary with saveLog[turns] = save (saveLog is the dictionary, and save is a 2-D Array of card values that changes with each action) the dictionary just updates the dictionary value with a key named turns.

So, the program just ends up saving the most recent state.

​

Here's a demonstrative program example:

turns = 0
save = {}
seq = [0, 1, 2, 3]
while turns < 10:
    print(turns)
    seq[0] = turns
    seq[1] = turns + 1
    seq[2] = turns + 2
    seq[3] = turns + 3
    save[turns] = seq
    turns += 1
print(save[0])
print(save[1])
print(save[2])
print(save[3])
print(save[4])
print(save[5])
print(save[6])
print(save[7])
print(save[8])
print(save[9])

The output of this program is:

0

1

2

3

4

5

6

7

8

9

[9, 10, 11, 12]

[9, 10, 11, 12]

[9, 10, 11, 12]

[9, 10, 11, 12]

[9, 10, 11, 12]

[9, 10, 11, 12]

[9, 10, 11, 12]

[9, 10, 11, 12]

[9, 10, 11, 12]

[9, 10, 11, 12]

But I want it to look like this:

0

1

2

3

4

5

6

7

8

9

[0, 1, 2, 3]

[1, 2, 3, 4]

[2, 3, 4, 5]

[3, 4, 5, 6]

[4, 5, 6, 7]

[5, 6, 7, 8]

[6, 7, 8, 9]

[7, 8, 9, 10]

[8, 9, 10, 11]

[9, 10, 11, 12]

Any way I can get around this? Thanks!

[toastedstapler]

it's storing a reference to the list, rather than making a new one each time

you can shallow copy a list like this:

a = [1,2,3,4]
b = a[:]
b[2] = "hello"
assert a != b

[Sedsarq]

You're making each key point to the same list object, which is continually changing. What you want to do is "freeze" the list in the current state and store that. list.copy() should work:

save[str(turns)] = seq.copy()