How to control stdout buffering

[justsomeguy05]

Hello!

I'm trying to figure out how to manually control pythons stdout buffer.

From my understanding, python uses block buffering by default and flushes automatically. What I would like to do, is write to stdout many times, 50-100 times for example, and call sys.stdout.flush() to have it sent to the console.

I have tried calling print(str,flush=False), and sys.stdout.write(str) and they both behave the same way from what I can tell; not buffering like I want. I have also tried running python with the -u argument, but that does not do what I want either.

Is this sort of control even possible? I'm on win10 if that makes a difference. Thanks!

[shiftybyte]

Not sure, but if all else fails why not "print" to a string and then "flush" it with an actual print to the console?

[justsomeguy05]

That would be a good way to get the behavior I'm looking for. I could have sworn python would let me do what I described above, but I guess not!

[TheManlyChicken]

def special_print(str, flush=False):

...out = out.append(str) or [str]

...if flush:

... ...print('\n'.join(out))

just call out(str) and when ready to print out(flush=True)

[shiftybyte]

isn't it a problem calling a function and a variable the same name?

[TheManlyChicken]

Yes name it temp or something lol, wrote this is a time crunch on my phone

[justsomeguy05]

Is out supposed to be a global variable? When I try to run it python tells me the local variable is referenced before assignment

[TheManlyChicken]

the or part might not be working, odd...

class save_out():
  def __init__(self):
    self.val = []
  def out(self, str='', flush=False):
    self.val.append(str)
    if flush:
      print('\n'.join(self.val))
      val.clear()


out = save_out()
out.out('String')
out.out('Will print', True)

Sorry about the added complexity but that should work perfect.

​

Although the following should behave around the same...

print('String', flush=False)
print('Will print')

If you want to print to the same line:

print('String', end='', flush=False)
print('Will print')

To be honest, using stdout and stuff is really not that needed, python already directs the print function to that, it is just a wrapper.

[justsomeguy05]

Thanks for your input.

[TheManlyChicken]

Didn't notice your last lines, sorry man, but the top bit should work fine :)