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Comment by bonzini | Hacker News Reader

It would actually be doable in 2-3 lines using Unicode characters 2571 and 2572 (both hex), respectively "╱" and "╲".

  import sys, random

  while True:
      sys.stdout.write(random.choice([u'\u2571', u'\u2572']))
      sys.stdout.flush()

They're called box drawing characters, it's how ncurses applications draw their GUI.

https://en.wikipedia.org/wiki/Box-drawing_character

# Without unicode or pygame (using Python3)

  import sys, random
  while True :
    print( random.choice( [ chr( 92 ) , chr( 47 ) ] ) , end = "" )
    sys.stdout.flush( )

This one doesn't look correct in the terminal though as the characters don't join up

(parent):

  ╱╱╱╲╲╲╲╲╲╱╲╲╲╱╱╱╲╱╱╱╲╲╲
  ╱╱╲╲╲╲╲╲╲╲╱╱╲╲╲╱╲╲╱╱╲╲╲

vs (yours)

  \\\/\\\//\//\\///\\\\////\
  /\////\\\//\\\/\/\/\\\\/

Also in the terminal there isn't the space between the lines for the parent either (that's just HN formatting), but there is a space when using \ or /

That's because of HN formatting.

It's because u'\u2571' is a different character from chr(92)

The C64 font is (almost?) square, this also contributes to the nice effect.

It's square as it's 8x8 pixels, but the pixels themselves are not. There's a difference in aspect ratio between PAL and NTSC variants, and because the C64 was usually connected to a CRT, pretty much all bets are off.

  import random
  while True:
      print(random.choice("╱╲"), end="")

How's that for readability?

That's cool, didn't realize HN would allow that.

Here's a smaller one:

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

Why flush?

I initially put a sleep in, it's unnecessary in this case.

In some terminals, python buffers the output until it has enough and then dumps it to the console. IIRC it is like this because the console can be pretty slow, so by buffering you can do more calculations instead of always waiting for the console.

It should always flush at the end of the line though, no?

    (loop (princ (char "╱╲" (random 2))))

... or, if you use alexandria (a popular set of utilities)

    (loop (princ (random-elt "╱╲")))

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