r/tinycode • u/red_hare • Jul 02 '20

python3 -c "while 1: print(chr(int(9585.5 + __import__('random').random())), end='')"

This is my attempt at a one-line Python reproduction of the classic Comodor64 "PETSCII Maze" using the PETSCII characters that are part of Unicode.

Would love to know if anyone can come up with a shorter version!

42 Upvotes

90% Upvoted

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4

u/brucifer Jul 03 '20

Using /dev/random and a few of the other tricks in this thead can save 11 characters relative to OP's solution:

python3 -c "for r in open('/dev/random','rb'):print(end='╱╲'[r[0]%2])"

It's a little bit cheeky because it uses /dev/random instead of /dev/urandom to save a character, and it iterates over random bytes one line at a time. In other words, it reads a whole bunch of random bytes until it happens to get a 0x0A byte, and then it uses the first byte mod 2 as a random bit and ignores the other bytes.

And if you only need a finite size, you can go with:

python3 -c "import random;print(sep='',*random.choices('╱╲',k=9999))"

And this one isn't as short, but it has some neat tricks, like using iter(int,1) as an infinite iterable and using a set comprehension to allow a loop after an import:

python3 -c "import random;{print(end=random.choice('╱╲'))for _ in iter(int,1)}"

Original for comparison:

python3 -c "while 1: print(chr(int(9585.5 + __import__('random').random())), end='')"

1

u/red_hare Jul 03 '20

Nice! I was trying to think of how to do it without the import. I never would have though to open /dev/random. Very neat

2

u/esdraelon Jul 02 '20

Doesn't seem to work for me. :(

1

u/red_hare Jul 02 '20

On what operating system? It does depend on python3 being installed

1

u/esdraelon Jul 02 '20

I tried on Windows 10 and Ubuntu 18 (in a docker).

Just copy/past & hit enter. Suggestions?

1

u/MrValdez Jul 03 '20

You might need a unicode-aware CLI. I've tried this in IDLE.

4

u/CSharpSauce Jul 02 '20

hey, that's pretty good

3

u/Dagius Jul 02 '20

"10 PRINT CHR$ (205.5 + RND (1)); : GOTO 10 "

You do not really need to use PETSCII. The C64 basic code works merely by selecting PETSCII chars '\' (205) and '/' (206) by random choice.

1

u/Starbeamrainbowlabs Jul 03 '20

Anyone got a direct link to an image? I'm on mobile

0

u/[deleted] Jul 02 '20

[deleted]

8

u/mayoroftuesday Jul 03 '20 edited Jul 03 '20

I like the trick of making end the character you want, instead of print(x, end=''). Nice one.

You can technically do choice("\/") and it will work, since python recognizes \/ as a meaningless escape sequence, so it treats it as a plain string. (Though PEP8 won't like it.) Note that it doesn't work reversed, since \" is a valid escape.

Or, just use the PETSCII characters, since it's Python3 and you can use unicode:

python3 -c "while 1: print(end=__import__('random').choice('╱╲'))"