what does "lost sys.stdin" error mean?
lynvie
python 3 (I'm a novice). I called the program tmp.py and the data
input file is sum.dat (just a list of numbers, 1 per line). When I
type into my command shell "tmp.py < sum.dat" I get an error from
"line=input()" -- that's line 7 from the code below. The exact error
message is:
RuntimeError: input(): lost sys.stdin.
print("Type integers, each followed by Enter; or ^D or ^Z to finish")
total=0
count=0
while True:
try:
line=input()
if line:
number=int(line)
total += number
count += 1
print("number =",number)
except ValueError as err:
print(err)
continue
except EOFError:
break
if count:
print("count =", count, "total =", total, "mean =", total/
count)
Tim Harig
> I have a very simple program from the first chapter of a book on
> python 3 (I'm a novice). I called the program tmp.py and the data
> input file is sum.dat (just a list of numbers, 1 per line). When I
> type into my command shell "tmp.py < sum.dat" I get an error from
What OS are you using? I know that pipes cause issues when working with
interpreters on Windows. You must call the python interpreter directly or
it will not be able to handle the pipe directly. I don't remember exacly
how the issue manifests but I remember it has bitten me before on Win32. I
don't currenlty have a Windows machine to test on.
> "line=input()" -- that's line 7 from the code below. The exact error
> message is:
> RuntimeError: input(): lost sys.stdin.
I am working on Linux and I have been unable to produce your error. My
Python version identifies itself as:
>>> import sys
>>> sys.version
'3.0.1 (r301:69556, Mar 17 2009, 11:42:03) \n[GCC 4.1.2]'
This is what I have done using your same tmp.py file as pasted from
a shell session:
17:52,505$ count=0
17:53,506$ while [ $count -lt 20 ]; do
echo $RANDOM >> sum.dat;
newcount=`echo "$count + 1" | bc`;
count=$newcount;
done
17:53,507$ python3.0 tmp.py < sum.dat
Type integers, each followed by Enter; or ^D or ^Z to finish
number = 22657
count = 1 total = 22657 mean = 22657.0
number = 12223
count = 2 total = 34880 mean = 17440.0
number = 10250
count = 3 total = 45130 mean = 15043.3333333
number = 20919
count = 4 total = 66049 mean = 16512.25
number = 20995
count = 5 total = 87044 mean = 17408.8
number = 28988
count = 6 total = 116032 mean = 19338.6666667
number = 13015
count = 7 total = 129047 mean = 18435.2857143
number = 25701
count = 8 total = 154748 mean = 19343.5
number = 6566
count = 9 total = 161314 mean = 17923.7777778
number = 19396
count = 10 total = 180710 mean = 18071.0
number = 16771
count = 11 total = 197481 mean = 17952.8181818
number = 2039
count = 12 total = 199520 mean = 16626.6666667
number = 655
count = 13 total = 200175 mean = 15398.0769231
number = 27417
count = 14 total = 227592 mean = 16256.5714286
number = 5000
count = 15 total = 232592 mean = 15506.1333333
number = 12015
count = 16 total = 244607 mean = 15287.9375
number = 8746
count = 17 total = 253353 mean = 14903.1176471
number = 29487
count = 18 total = 282840 mean = 15713.3333333
number = 3194
count = 19 total = 286034 mean = 15054.4210526
number = 8225
count = 20 total = 294259 mean = 14712.95
As you can see, it seems to be working as prescribed.
Tim Harig
> On 2009-06-11, lynvie <lyndi...@gmail.com> wrote:
>> I have a very simple program from the first chapter of a book on
>> python 3 (I'm a novice). I called the program tmp.py and the data
>> input file is sum.dat (just a list of numbers, 1 per line). When I
>> type into my command shell "tmp.py < sum.dat" I get an error from
> What OS are you using? I know that pipes cause issues when working with
> interpreters on Windows. You must call the python interpreter directly or
> it will not be able to handle the pipe directly. I don't remember exacly
> how the issue manifests but I remember it has bitten me before on Win32. I
> don't currenlty have a Windows machine to test on.
More info:
http://groups.google.co.uk/group/comp.lang.python/browse_frm/thread/10d3928277319bef
lynvie
Thanks for the additional info! I had no idea this was an old Windows
problem... I'm using Windows XP and I'm up-to-date on all my patches.
The good news is I can invoke the script correctly now, thanks to your
help!
On Jun 11, 4:25 pm, Tim Harig <user...@ilthio.net> wrote:
> On 2009-06-11, Tim Harig <user...@ilthio.net> wrote:
>
> > On 2009-06-11, lynvie <lyndiech...@gmail.com> wrote:
> >> I have a very simple program from the first chapter of a book on
> >> python 3 (I'm a novice). I called the program tmp.py and the data
> >> input file is sum.dat (just a list of numbers, 1 per line). When I
> >> type into my command shell "tmp.py < sum.dat" I get an error from
> > What OS are you using? I know that pipes cause issues when working with
> > interpreters on Windows. You must call the python interpreter directly or
> > it will not be able to handle the pipe directly. I don't remember exacly
> > how the issue manifests but I remember it has bitten me before on Win32. I
> > don't currenlty have a Windows machine to test on.
>
> More info:http://groups.google.co.uk/group/comp.lang.python/browse_frm/thread/1...
Tim Harig
> Thanks for the additional info! I had no idea this was an old Windows
> problem... I'm using Windows XP and I'm up-to-date on all my patches.
s/problem/feature/
Steve Ballmer, CEO of Microsoft, would prefer that you think of it as a
'feature'.
This is a problem that I would suspect has plagued a lot of people because
it doesn't seem to be overly documented in any of the popular python
learning materials. Even Mark Hammond & Andy Robinson's book _Python
Programming on Win32_ doesn't mention the problem directly in its Windowes
gotchas section-- though it does mention there are a number of bugs in the
Windows implementation of popen().
> The good news is I can invoke the script correctly now, thanks to your
> help!
Happy Pythoning!