Emacs Python-mode. Newbie problem.

[Lacrima]

Hello!

I have just started using Emacs to write python scripts.
I installed python-mode.el

Then I just tried this code:

print 'hello world'

When I press C-c RET, new blank window is opened and emacs says:
(Shell command succeeded with no output)
So where is my 'hello world'?

When I do C-c C-c, it prints 'hello world' successfully.
Why in the first case I get no output?

Thanks in advance!

With regards, Max
(sorry if my English isn't very proper)

 

[Piet van Oostrum]

L> Hello!
L> I have just started using Emacs to write python scripts.
L> I installed python-mode.el

L> Then I just tried this code:

L> print 'hello world'

L> When I press C-c RET, new blank window is opened and emacs says:
L> (Shell command succeeded with no output)
L> So where is my 'hello world'?

L> When I do C-c C-c, it prints 'hello world' successfully.
L> Why in the first case I get no output?

Can you check in the buffer where you have the python code what command
C-c RET is bound to?
With C-h k C-c RET

Shell command succeeded with no output suggests that is has a different
binding than the standard one in python-mode.

Did you happen to name your file 'test' or 'test.py?

C-c RET does an import and 'import test' imports a standard module test.

 

[Lacrima]

Can you check in the buffer where you have the python code what command
C-c RET is bound to?
With C-h k C-c RET

Shell command succeeded with no output suggests that is has a different
binding than the standard one in python-mode.

Did you happen to name your file 'test' or 'test.py?

C-c RET does an import and 'import test' imports a standard module test.

Hi, Piet!

Thanks for your reply!
My file name is 'trains.py'.
When I do C-h k C-c RET, it shows me help from manual: "C-c RET runs
the command py-execute-import-or-reload
which is an interactive Lisp function in `python-mode'..." and so
on.

And still when I do C-c RET, I receive "(Shell command succeeded with
no output)"

Any more help would be really appreciated, because I am newbie with
Emacs.

With regards, Max

 

[Piet van Oostrum]

L> Thanks for your reply!
L> My file name is 'trains.py'.
L> When I do C-h k C-c RET, it shows me help from manual: "C-c RET runs
L> the command py-execute-import-or-reload
L> which is an interactive Lisp function in `python-mode'..." and so
L> on.

L> And still when I do C-c RET, I receive "(Shell command succeeded with
L> no output)"

L> Any more help would be really appreciated, because I am newbie with
L> Emacs.

I tested it and I can get this message also. It happens when you have no
Python shell running (*Python* buffer). The python code is then executed
by calling the python shell command and catching the output. This output
is displayed in the *Python Output* buffer. It happens also with C-c C-c
and it will give the same message.

There is a difference, however between C-c C-x and C-c RET: The latter
will import your module, and most modules are written such that
importing them doesn't print anything. If you add something like
print "test" and the end of file, then "test" will appear in the *Python
Output* buffer.

If your file has the print "hello world" statement it should display in
the *Python Output* buffer. I checked that.

On the other hand, if you have a python shell running you must make sure
(e.g. with the cd command) that its working directory is the directory
where your python file is located, otherwise the import statement will
not find your file. Unless it is somewhere in the python path. Also the
*Python* buffer will not automatically pop up if it is not visible, in
contrast with the *Python Output* buffer.

 

[Lacrima]

I tested it and I can get this message also. It happens when you have no
Python shell running (*Python* buffer). The python code is then executed
by calling the python shell command and catching the output. This output
is displayed in the *Python Output* buffer. It happens also with C-c C-c
and it will give the same message.

There is a difference, however between C-c C-x and C-c RET: The latter
will import your module, and most modules are written such that
importing them doesn't print anything. If you add something like
print "test" and the end of file, then "test" will appear in the *Python
Output*  buffer.

If your file has the print "hello world" statement it should display in
the *Python Output* buffer. I checked that.

On the other hand, if you have a python shell running you must make sure
(e.g. with the cd command) that its working directory is the directory
where your python file is located, otherwise the import statement will
not find your file. Unless it is somewhere in the python path. Also the
*Python* buffer will not automatically pop up if it is not visible, in
contrast with the *Python Output* buffer.

Thank you for really useful and detailed explanation. Now I can test
my code using Emacs.
But I think it works for me in a little bit different way.
My file contains only the print 'hello world'.
If I have no python shell running, then:
a) C-c RET opens *Python Output* buffer without any output and with
'Shell command succeeded with no output' message at the bottom
b) C-c C-c opens *Python Output* with appropriate 'hello world'
message.

Then I run python shell with C-c ! command. And:
a) C-c RET opens *Python* buffer and prints 'hello world' in the
python shell
b) C-c C-c gives the same result.

With regards, Max

 

[Piet van Oostrum]

L> Thank you for really useful and detailed explanation. Now I can test
L> my code using Emacs.
L> But I think it works for me in a little bit different way.
L> My file contains only the print 'hello world'.
L> If I have no python shell running, then:
L> a) C-c RET opens *Python Output* buffer without any output and with
L> 'Shell command succeeded with no output' message at the bottom
L> b) C-c C-c opens *Python Output* with appropriate 'hello world'
L> message.

L> Then I run python shell with C-c ! command. And:
L> a) C-c RET opens *Python* buffer and prints 'hello world' in the
L> python shell
L> b) C-c C-c gives the same result.

Which version of python-mode.el do you have? (Variable py-version)

 

[Lacrima]

Which version of python-mode.el do you have? (Variable py-version)

py-version's value is "5.1.0"

Also maybe the problem is because I use Emacs version 21.4.1. But I
can't change it to 22, because I access Emacs via SSH on some shared
hosting service.

With regards, Max.