How to launch an EDITOR (e. g. vim) from a python script?
Question:
I want to call up an editor in a python script to solicit input from the user, much like crontab e or git commit does.
Here’s a snippet from what I have running so far. (In the future, I might use $EDITOR instead of vim so that folks can customize to their liking.)
tmp_file = '/tmp/up.'+''.join(random.choice(string.ascii_uppercase + string.digits) for x in range(6))
edit_call = [ "vim",tmp_file]
edit = subprocess.Popen(edit_call,stdin=subprocess.PIPE, stdout=subprocess.PIPE, shell=True )
My problem is that by using Popen, it seems to keep my i/o with the python script from going into the running copy of vim, and I can’t find a way to just pass the i/o through to vim. I get the following error.
Vim: Warning: Output is not to a terminal
Vim: Warning: Input is not from a terminal
What’s the best way to call a CLI program from python, hand control over to it, and then pass it back once you’re finished with it?
Answers:
The PIPE is the problem. VIM is an application that depends on the fact that the stdin/stdout channels are terminals and not files or pipes. Removing the stdin/stdout paramters worked for me.
I would avoid using os.system as it should be replaced by the subprocess module.
Calling up $EDITOR is easy. I’ve written this kind of code to call up editor:
import sys, tempfile, os
from subprocess import call
EDITOR = os.environ.get('EDITOR', 'vim') # that easy!
initial_message = '' # if you want to set up the file somehow
with tempfile.NamedTemporaryFile(suffix=".tmp") as tf:
tf.write(initial_message)
tf.flush()
call([EDITOR, tf.name])
# do the parsing with `tf` using regular File operations.
# for instance:
tf.seek(0)
edited_message = tf.read()
The good thing here is the libraries handle creating and removing the temporary file.
In python3: 'str' does not support the buffer interface
$ python3 editor.py
Traceback (most recent call last):
File "editor.py", line 9, in <module>
tf.write(initial_message)
File "/usr/lib/python3.4/tempfile.py", line 399, in func_wrapper
return func(*args, **kwargs)
TypeError: 'str' does not support the buffer interface
For python3, use initial_message = b"" to declare the buffered string.
Then use edited_message.decode("utf-8") to decode the buffer into a string.
import sys, tempfile, os
from subprocess import call
EDITOR = os.environ.get('EDITOR','vim') #that easy!
initial_message = b"" # if you want to set up the file somehow
with tempfile.NamedTemporaryFile(suffix=".tmp") as tf:
tf.write(initial_message)
tf.flush()
call([EDITOR, tf.name])
# do the parsing with `tf` using regular File operations.
# for instance:
tf.seek(0)
edited_message = tf.read()
print (edited_message.decode("utf-8"))
Result:
$ python3 editor.py
look a string
Package python-editor:
$ pip install python-editor
$ python
>>> import editor
>>> result = editor.edit(contents="text to put in editorn")
More details here: https://github.com/fmoo/python-editor
click is a great library for command line processing and it has some utilities, click.edit() is portable and uses the EDITOR environment variable. I typed the line, stuff, into the editor. Notice it is returned as a string. Nice.
(venv) /tmp/editor $ export EDITOR='=mvim -f'
(venv) /tmp/editor $ python
>>> import click
>>> click.edit()
'stuffn'
Check out the docs https://click.palletsprojects.com/en/7.x/utils/#launching-editors My entire experience:
/tmp $ mkdir editor
/tmp $ cd editor
/tmp/editor $ python3 -m venv venv
/tmp/editor $ source venv/bin/activate
(venv) /tmp/editor $ pip install click
Collecting click
Using cached https://files.pythonhosted.org/packages/fa/37/45185cb5abbc30d7257104c434fe0b07e5a195a6847506c074527aa599ec/Click-7.0-py2.py3-none-any.whl
Installing collected packages: click
Successfully installed click-7.0
You are using pip version 19.0.3, however version 19.3.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
(venv) /tmp/editor $ export EDITOR='=mvim -f'
(venv) /tmp/editor $ python
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 16:52:21)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import click
>>> click.edit()
'stuffn'
>>>
The accepted answer does not work for me. edited_message stays the same as initial_message. As explained in the comments, this is caused by vim saving strategy.
There are possible workarounds, but they are not portable to other editors. Instead, I strongly recommend to use click.edit function. With it, your code will look like this:
import click
initial_message = "edit me!"
edited_message = click.edit(initial_message)
print(edited_message)
Click is a third-party library, but you probably should use it anyway if you are writing a console script. click to argparse is the same as requests to urllib.
I want to call up an editor in a python script to solicit input from the user, much like crontab e or git commit does.
Here’s a snippet from what I have running so far. (In the future, I might use $EDITOR instead of vim so that folks can customize to their liking.)
tmp_file = '/tmp/up.'+''.join(random.choice(string.ascii_uppercase + string.digits) for x in range(6))
edit_call = [ "vim",tmp_file]
edit = subprocess.Popen(edit_call,stdin=subprocess.PIPE, stdout=subprocess.PIPE, shell=True )
My problem is that by using Popen, it seems to keep my i/o with the python script from going into the running copy of vim, and I can’t find a way to just pass the i/o through to vim. I get the following error.
Vim: Warning: Output is not to a terminal
Vim: Warning: Input is not from a terminal
What’s the best way to call a CLI program from python, hand control over to it, and then pass it back once you’re finished with it?
The PIPE is the problem. VIM is an application that depends on the fact that the stdin/stdout channels are terminals and not files or pipes. Removing the stdin/stdout paramters worked for me.
I would avoid using os.system as it should be replaced by the subprocess module.
Calling up $EDITOR is easy. I’ve written this kind of code to call up editor:
import sys, tempfile, os
from subprocess import call
EDITOR = os.environ.get('EDITOR', 'vim') # that easy!
initial_message = '' # if you want to set up the file somehow
with tempfile.NamedTemporaryFile(suffix=".tmp") as tf:
tf.write(initial_message)
tf.flush()
call([EDITOR, tf.name])
# do the parsing with `tf` using regular File operations.
# for instance:
tf.seek(0)
edited_message = tf.read()
The good thing here is the libraries handle creating and removing the temporary file.
In python3: 'str' does not support the buffer interface
$ python3 editor.py
Traceback (most recent call last):
File "editor.py", line 9, in <module>
tf.write(initial_message)
File "/usr/lib/python3.4/tempfile.py", line 399, in func_wrapper
return func(*args, **kwargs)
TypeError: 'str' does not support the buffer interface
For python3, use initial_message = b"" to declare the buffered string.
Then use edited_message.decode("utf-8") to decode the buffer into a string.
import sys, tempfile, os
from subprocess import call
EDITOR = os.environ.get('EDITOR','vim') #that easy!
initial_message = b"" # if you want to set up the file somehow
with tempfile.NamedTemporaryFile(suffix=".tmp") as tf:
tf.write(initial_message)
tf.flush()
call([EDITOR, tf.name])
# do the parsing with `tf` using regular File operations.
# for instance:
tf.seek(0)
edited_message = tf.read()
print (edited_message.decode("utf-8"))
Result:
$ python3 editor.py
look a string
Package python-editor:
$ pip install python-editor
$ python
>>> import editor
>>> result = editor.edit(contents="text to put in editorn")
More details here: https://github.com/fmoo/python-editor
click is a great library for command line processing and it has some utilities, click.edit() is portable and uses the EDITOR environment variable. I typed the line, stuff, into the editor. Notice it is returned as a string. Nice.
(venv) /tmp/editor $ export EDITOR='=mvim -f'
(venv) /tmp/editor $ python
>>> import click
>>> click.edit()
'stuffn'
Check out the docs https://click.palletsprojects.com/en/7.x/utils/#launching-editors My entire experience:
/tmp $ mkdir editor
/tmp $ cd editor
/tmp/editor $ python3 -m venv venv
/tmp/editor $ source venv/bin/activate
(venv) /tmp/editor $ pip install click
Collecting click
Using cached https://files.pythonhosted.org/packages/fa/37/45185cb5abbc30d7257104c434fe0b07e5a195a6847506c074527aa599ec/Click-7.0-py2.py3-none-any.whl
Installing collected packages: click
Successfully installed click-7.0
You are using pip version 19.0.3, however version 19.3.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
(venv) /tmp/editor $ export EDITOR='=mvim -f'
(venv) /tmp/editor $ python
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 16:52:21)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import click
>>> click.edit()
'stuffn'
>>>
The accepted answer does not work for me. edited_message stays the same as initial_message. As explained in the comments, this is caused by vim saving strategy.
There are possible workarounds, but they are not portable to other editors. Instead, I strongly recommend to use click.edit function. With it, your code will look like this:
import click
initial_message = "edit me!"
edited_message = click.edit(initial_message)
print(edited_message)
Click is a third-party library, but you probably should use it anyway if you are writing a console script. click to argparse is the same as requests to urllib.