A completely silly question

[Amir Dekel]

This must be the silliest question ever:

What about user input in Python? (like stdin)
Where can I find it? I can't find any references to it in the documentation.

Amir

[Frans Englich]

Re: A completely silly question

On Friday 17 December 2004 16:40, Amir Dekel wrote:[color=blue]
> This must be the silliest question ever:
>
> What about user input in Python? (like stdin)
> Where can I find it? I can't find any references to it in the
> documentation.[/color]

See sys.stdin


Cheers,

Frans

[Harlin Seritt]

Re: A completely silly question

Amir Dekel wrote:
[color=blue]
> This must be the silliest question ever:
>
> What about user input in Python? (like stdin)
> Where can I find it? I can't find any references to it in the
> documentation.
>
> Amir[/color]

Simple, Simple, Simple:

Var = raw_input("Some prompting text here: ")


--
Harlin Seritt

[Amir Dekel]

Re: A completely silly question

Harlin Seritt wrote:
[color=blue]
>
> Simple, Simple, Simple:
>
> Var = raw_input("Some prompting text here: ")
>[/color]

Frans Englich wrote:[color=blue]
>
> See sys.stdin
>[/color]

What I need from the program is to wait for a single character input,
something like while(getchar() ) in C. All those Python modules don't
make much sence to me...

Amir

[Steven Bethard]

Re: A completely silly question

Amir Dekel wrote:[color=blue]
> What I need from the program is to wait for a single character input,
> something like while(getchar() ) in C. All those Python modules don't
> make much sence to me...[/color]

sys.stdin.read( 1)

but if you're having trouble reading the module documentation, maybe you
could elaborate on what's giving you trouble. The answer to 99% of
questions on this list is in the documentation somewhere, so if you
don't know how to read it, you're going to have trouble with Python.

Steve

[Peter Hansen]

Re: A completely silly question

Amir Dekel wrote:[color=blue]
> What I need from the program is to wait for a single character input,
> something like while(getchar() ) in C.[/color]

Try the "msvcrt" module if you are on Windows.

If you are not, remember to specify your platform next time
you ask a question...
[color=blue]
> All those Python modules don't
> make much sence to me...[/color]

That's going to make it hard to program in Python, I suspect.
Maybe it would be helpful to run through the tutorial, or
spend more time reading the docs.

-Peter

[Mike Meyer]

Re: A completely silly question

Steven Bethard <steven.bethard @gmail.com> writes:
[color=blue]
> Amir Dekel wrote:[color=green]
>> What I need from the program is to wait for a single character
>> input, something like while(getchar() ) in C. All those Python
>> modules don't make much sence to me...[/color]
>
> sys.stdin.read( 1)[/color]

That doesn't do what he wants, because it doesn't return until you hit
a newline.

The answer is system dependent. Or you can use massive overkill and
get curses, but if you're on windows you'll have to use a third party
curses package, and maybe wrap it


--
Mike Meyer <mwm@mired.or g> http://www.mired.org/home/mwm/
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.

[wes weston]

Re: A completely silly question

Amir Dekel wrote:[color=blue]
> Harlin Seritt wrote:
>[color=green]
>>
>> Simple, Simple, Simple:
>>
>> Var = raw_input("Some prompting text here: ")
>>[/color]
>
> Frans Englich wrote:[color=green]
> >
> > See sys.stdin
> >[/color]
>
> What I need from the program is to wait for a single character input,
> something like while(getchar() ) in C. All those Python modules don't
> make much sence to me...
>
> Amir[/color]

Amir,
[color=blue][color=green][color=darkred]
>>> import tkSimpleDialog
>>> ch = tkSimpleDialog. askstring("","c h?")[/color][/color][/color]

wes

[marco]

Re: A completely silly question

Amir Dekel wrote:
[color=blue]
>
> What I need from the program is to wait for a single character input,
> something like while(getchar() ) in C. All those Python modules don't
> make much sence to me...[/color]

Take a look at Alan Gauld's "Learning to Program"
(http://www.freenetpages.co.uk/hp/alan.gauld/)
in the section "Event Driven programming"

Hope it helps

Marco

[Steven Bethard]

Re: A completely silly question

Mike Meyer wrote:[color=blue]
> That doesn't do what he wants, because it doesn't return until you hit
> a newline.[/color]

Are you sure that's not just an artifact of how your terminal buffers
data for sys.stdin?

$ cat temp.py
import sys
char = sys.stdin.read( 1)
while char:
print char
char = sys.stdin.read( 1)
$ cat temp.txt
abc
def
$ python temp.py < temp.txt
a
b
c


d
e
f

Of course if the intent is to have this work with terminal input, then
yes, sys.stdin.read( 1) is probably not going to do the right thing...

Steve

[Mike Meyer]

Re: A completely silly question

Steven Bethard <steven.bethard @gmail.com> writes:
[color=blue]
> Mike Meyer wrote:[color=green]
>> That doesn't do what he wants, because it doesn't return until you hit
>> a newline.[/color]
> Of course if the intent is to have this work with terminal input, then
> yes, sys.stdin.read( 1) is probably not going to do the right thing...[/color]

That's what the OP asked for - a way to wait for a single character,
like while(getchar() ) in C.

Hmm. That tells me he's probably on a Windows box, so my unix solution
wouldn't do him much good.

<mike
--
Mike Meyer <mwm@mired.or g> http://www.mired.org/home/mwm/
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.

[Amir Dekel]

Re: A completely silly question

Mike Meyer wrote:
[color=blue]
>
> Hmm. That tells me he's probably on a Windows box, so my unix solution
> wouldn't do him much good.
>[/color]
Yes, Windows...too bad

[David Bolen]

Re: A completely silly question

Mike Meyer <mwm@mired.or g> writes:
[color=blue]
> Steven Bethard <steven.bethard @gmail.com> writes:
>[color=green]
> > Amir Dekel wrote:[color=darkred]
> >> What I need from the program is to wait for a single character
> >> input, something like while(getchar() ) in C. All those Python
> >> modules don't make much sence to me...[/color]
> >
> > sys.stdin.read( 1)[/color]
>
> That doesn't do what he wants, because it doesn't return until you hit
> a newline.[/color]

Well, but that's true as well for getchar() (at least in many cases of
interactive input and line buffering), so in that respect I do think
it's a fairly direct replacement, depending on how the OP was going to
use getchar() in the application.

For example, compare: with:

#include <stdio.h> >>> import sys[color=blue][color=green][color=darkred]
>>> while 1:[/color][/color][/color]
main() ... c = sys.stdin.read( 1)
{ ... print ord(c),
while (1) { ...
int ch = getchar();
printf("%d ",ch);
}
}

When run, both produce (at least for me):

0123456789 (hit Enter here)
48 49 50 51 52 53 54 55 56 57 10

under both Unix (at least FreeBSD/Linux in my quick tests) and Windows
(whether MSVC or Cygwin/gcc).

(I don't include any output buffer flushing, since it shouldn't be
needed on an interactive terminal, but you could add that to ensure
that it isn't the output part that is being buffered - I did try it
just to be sure on the Unix side)
[color=blue]
> The answer is system dependent. Or you can use massive overkill and
> get curses, but if you're on windows you'll have to use a third party
> curses package, and maybe wrap it[/color]

If you want to guarantee you'll get the next console character without
any waiting under Windows there's an msvcrt module that contains
functions like kbhit() and getch[e] that would probably serve.

-- David

[Mike Meyer]

Re: A completely silly question

David Bolen <db3l@fitlinxx. com> writes:
[color=blue]
> Mike Meyer <mwm@mired.or g> writes:
>[color=green]
>> Steven Bethard <steven.bethard @gmail.com> writes:
>>[color=darkred]
>> > Amir Dekel wrote:
>> >> What I need from the program is to wait for a single character
>> >> input, something like while(getchar() ) in C. All those Python
>> >> modules don't make much sence to me...
>> >
>> > sys.stdin.read( 1)[/color]
>>
>> That doesn't do what he wants, because it doesn't return until you hit
>> a newline.[/color]
>
> Well, but that's true as well for getchar() (at least in many cases of
> interactive input and line buffering), so in that respect I do think
> it's a fairly direct replacement, depending on how the OP was going to
> use getchar() in the application.[/color]

The OP said "wait for a single character input". sys.stdin.read( 1)
waits for a newline.

<mike
--
Mike Meyer <mwm@mired.or g> http://www.mired.org/home/mwm/
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.

[Fredrik Lundh]

Re: A completely silly question

>> Well, but that's true as well for getchar() (at least in many cases of[color=blue][color=green]
>> interactive input and line buffering), so in that respect I do think
>> it's a fairly direct replacement, depending on how the OP was going to
>> use getchar() in the application.[/color]
>
> The OP said "wait for a single character input". sys.stdin.read( 1)
> waits for a newline.[/color]

in the same same sentence, the OP also said that he wanted something like
C's getchar(). if you guys are going to read only parts of the original post,
you could at least try to read an entire sentence, before you start arguing...

</F>