In Python, how can I print out a board of numbers representing tic-tac-toe, with a "|" in between each number?

Question

I want to be able to rewrite the code in as few lines as possible, possibly in list comprehension syntax. Here is what the output should be:

1|2|3  
4|5|6  
7|8|9

This is what I have thought up. The separator doesn't actually print the "|". Any suggestions?

for i in [1,2,3,4,5,6,7,8,9]:
    print(i, sep = "|", end = "")
    if (i) % 3 == 0:
        print()

Answer 1

Just print it.

>>> print('1|2|3\n4|5|6\n7|8|9')
1|2|3
4|5|6
7|8|9

To clarify: Yes, I'm obviously assuming that really exactly these numbers shall be printed. I think it's a reasonable assumption, given that the OP also only showed those numbers both in the desired output and in the code, didn't say anything about more flexibility (really should have if it were required), and tic-tac-toe has X and O, not numbers. I suspect this is for showing the user which number to enter for which field during play.

Answer 2

>>> numbers = range(1, 10)

>>> print(('{}|{}|{}\n' * 3).format(*numbers))
1|2|3
4|5|6
7|8|9

Answer 3

I like format the most because it offers the best flexibility:

moves = [' ', ' ',' ',' ', 'x',' ',' ', ' ','o']
board = "|{}|{}|{}|\n|{}|{}|{}|\n|{}|{}|{}|\n"
print(board.format(*moves)

Modify the items in that list and run that same print statement for an on-the-go solution.

And there, I managed to slim it down to 3 lines. If I wasn't initializing the list, it would only be 2 lines.

Answer 4

the easiest and most elegant way to do it in python 3 using print:

for i in 1,4,7:
    print(i,i+1,i+2, sep='|')

Or using range:

for i in range(1,10,3):
    print(*range(i,i+3), sep='|')

Also there is a good reading here about iterable unpacking operator: Additional Unpacking

Also here is one-liner, not the shortest one but very readable:

print('\n'.join(('{}|{}|{}'.format(i,i+1,i+2) for i in (1,4,7))))

And original one-liner from @Stefan Pochmann's comment:

print(('{}|{}|{}\n' * 3).format(*range(1, 10)), end='')

Output for all is the same:

1|2|3
4|5|6
7|8|9

Answer 5

sep doesn't work when you only give a single thing to print

>>>print(1, sep='|')
1
>>> print(1,2,3, sep='|')
1|2|3

---

Could do this instead

for i in range(1,10):
    if i % 3 == 0:
        print(i, end="\n")
    else:
        print(i, end="|")

Shortening to a ternary

for i in range(1,10):
    print(i, end="\n") if i % 3 == 0 else print(i, end="|")

Output

1|2|3
4|5|6
7|8|9

Answer 6

print('\n'.join(['|'.join([str(c) for c in s[i:i+3]]) for i in range(0,9,3)]))

Don't use this (but it works). This assumes your array is in a variable named s

Answer 7

If you want something that is purely the smallest amount of lines, you can use the ternary syntax:

for i in range(1,10):
    print(i,end='|\n') if (i) % 3 == 0 else print(i,end = "|")

Output:

1|2|3
4|5|6
7|8|9

Answer 8

If we're going to code golf, lets code golf properly...

One line:

print("".join(str(i)+'\n|'[i%3>0]for i in range(1,10)))

You can make it one character shorter when you realise that the indexer >0 is actually longer than repeating the pipe (|):

print("".join(str(i)+'\n||'[i%3]for i in range(1,10)))

This gives:

1|2|3
4|5|6
7|8|9

If you need even shorter, a for loop technically doesn't need to be on a new line, also in Python 3 print will print every *args, until the *kwargs.

for i in range(1,10,3):print(i,i+1,i+2,sep='|')
pass # Pass not needed, just shows syntactically how it works.

The first line above is probably the shortest you can get, without just printing the string as is.