Re: [Tutor] Using venv
On 05/29/2017 08:09 PM, Ben Finney wrote: You should probably disregard this message as I have since solved the problem I was asking about. I originally wrote this message on 01/27/17, how it make it back to the list I don't know. Regards, Jim Jim writes: It has been suggested to me that I should use a virtual environment and venv would be a good choice. I've read through PEP405 and this link [1]. One possible confusion is the terminology. You have “a virtual environment” when you create one. The ‘venv’ module is not itself a virtual environment; it is what you use to create one :-) Though some of it seems a little confusing to me, I'm sure I can get it up and running. This question seems a little dumb and maybe I am being a little dense, but then what? * In each shell where you want to be working in that virtual Python environment, activate the virtualenv (by running the commands from its corresponding ‘activate’ script; e.g. ‘source $VENV/bin/activate’). * Do things requiring Python. Your program/script is done how do you run it? Do you always have to activate your venv and run it from there? To get the benefits of that particular virtualenv, yes. I like to run Tkinter programs from a launcher. Would that be possible and what would the command look like? How are the programs installed? Can you customise how they're launched? Lately I have been writing some Libreoffice calc macros and evaluating pyspread for it's macro capability. Would modules installed in my venv be available to the spreadsheet programs? The trick is that the environment variables for a process need to be set either when the program starts, or within the program; it can't be done externally. That isn't special to Python, it is how processes work. The virtualenv is activated by setting particular shell environment variables to specific values. If you can do that, the answer is yes. The ‘source $VENV/bin/activate’ command just runs shell commands to set those environment variables. It's not the only way to set those environment variables. Other Python-bundled programs, like LibreOffice or Blender, will likely have their own ways of activating a virtualenv; or at least you'll probably find people in those communities discussing how to do it. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Using venv
Jim writes: > It has been suggested to me that I should use a virtual environment > and venv would be a good choice. I've read through PEP405 and this > link [1]. One possible confusion is the terminology. You have “a virtual environment” when you create one. The ‘venv’ module is not itself a virtual environment; it is what you use to create one :-) > Though some of it seems a little confusing to me, I'm sure I can get > it up and running. This question seems a little dumb and maybe I am > being a little dense, but then what? * In each shell where you want to be working in that virtual Python environment, activate the virtualenv (by running the commands from its corresponding ‘activate’ script; e.g. ‘source $VENV/bin/activate’). * Do things requiring Python. > Your program/script is done how do you run it? Do you always have to > activate your venv and run it from there? To get the benefits of that particular virtualenv, yes. > I like to run Tkinter programs from a launcher. Would that be possible > and what would the command look like? How are the programs installed? Can you customise how they're launched? > Lately I have been writing some Libreoffice calc macros and evaluating > pyspread for it's macro capability. Would modules installed in my venv > be available to the spreadsheet programs? The trick is that the environment variables for a process need to be set either when the program starts, or within the program; it can't be done externally. That isn't special to Python, it is how processes work. The virtualenv is activated by setting particular shell environment variables to specific values. If you can do that, the answer is yes. The ‘source $VENV/bin/activate’ command just runs shell commands to set those environment variables. It's not the only way to set those environment variables. Other Python-bundled programs, like LibreOffice or Blender, will likely have their own ways of activating a virtualenv; or at least you'll probably find people in those communities discussing how to do it. -- \ “I distrust those people who know so well what God wants them | `\to do to their fellows, because it always coincides with their | _o__) own desires.” —Susan Brownell Anthony, 1896 | Ben Finney ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Using venv
On Fri, Jan 27, 2017 at 7:47 PM, Jim wrote: > > [...] This question seems a little dumb and maybe I am being a little dense, > but then what? Imagine that you are working on 5 different Python projects, each using different packages with different versions. We can break this down in two situations: 1. No virtualenv 1.a. You only have one Lib/site-packages to hold all your packages 1.b. Project A uses package-abc 1.2 while Project B uses package-abc 1.5 1.c. You go to work on Project B using package-abc 1.5, but later on you have to do some changes on Project A so you must downgrade package-abc to 1.2. Too bad you have to fix some bugs on Project B the next day, need to update package-abc back to 1.5 2. Virtualenv 2.a. You had multiple virtualenvs, each of them having their own Lib/site-packages 2.b. Project A uses one virtualenv with package-abc 1.2 while Project B uses another virtualenv with package-abc 1.5 2.c. You go to work on Project B using package-abc 1.5, so you activate its venv, but later on you have to do some changes on Project A so you activate the other venv. Too bad you have to fix some bugs on Project B the next day, activate Project B venv. It's a simple command to activate/deactivate a venv vs all the work you have to do when not using venv. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Using venv
On 01/27/2017 04:49 PM, Cameron Simpson wrote: On 27Jan2017 15:47, jim wrote: It has been suggested to me that I should use a virtual environment and venv would be a good choice. I've read through PEP405 and this link [1]. Though some of it seems a little confusing to me, I'm sure I can get it up and running. This question seems a little dumb and maybe I am being a little dense, but then what? Your program/script is done how do you run it? Do you always have to activate your venv and run it from there? I like to run Tkinter programs from a launcher. Would that be possible and what would the command look like? Lately I have been writing some Libreoffice calc macros and evaluating pyspread for it's macro capability. Would modules installed in my venv be available to the spreadsheet programs? The mere act of using the python from inside the venv invokes a python that runs off the venv, so all you really need to do is to contrive to execute that python instead of the system python where you want it. If your scripts start with something like this: #!/usr/bin/env python3 then you can simply contrive that "python3" is found from the virtualenv. You might put a symlink in your personal $HOME/bin directory, or source the venv's "activate" file from your shell's profile (this making the venv searched ahead of the system paths), etc. Or your launcher might simply invoke: $HOME/path/to/your/venv/bin/python your-tk-inter-script.py Cheers, Cameron Simpson Thank you. Got it up and running and tested it with a previously written Tkinter script, which works fine. Regards, Jim ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Using venv
On 27Jan2017 15:47, jim wrote: It has been suggested to me that I should use a virtual environment and venv would be a good choice. I've read through PEP405 and this link [1]. Though some of it seems a little confusing to me, I'm sure I can get it up and running. This question seems a little dumb and maybe I am being a little dense, but then what? Your program/script is done how do you run it? Do you always have to activate your venv and run it from there? I like to run Tkinter programs from a launcher. Would that be possible and what would the command look like? Lately I have been writing some Libreoffice calc macros and evaluating pyspread for it's macro capability. Would modules installed in my venv be available to the spreadsheet programs? The mere act of using the python from inside the venv invokes a python that runs off the venv, so all you really need to do is to contrive to execute that python instead of the system python where you want it. If your scripts start with something like this: #!/usr/bin/env python3 then you can simply contrive that "python3" is found from the virtualenv. You might put a symlink in your personal $HOME/bin directory, or source the venv's "activate" file from your shell's profile (this making the venv searched ahead of the system paths), etc. Or your launcher might simply invoke: $HOME/path/to/your/venv/bin/python your-tk-inter-script.py Cheers, Cameron Simpson ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
[Tutor] Using venv
It has been suggested to me that I should use a virtual environment and venv would be a good choice. I've read through PEP405 and this link [1]. Though some of it seems a little confusing to me, I'm sure I can get it up and running. This question seems a little dumb and maybe I am being a little dense, but then what? Your program/script is done how do you run it? Do you always have to activate your venv and run it from there? I like to run Tkinter programs from a launcher. Would that be possible and what would the command look like? Lately I have been writing some Libreoffice calc macros and evaluating pyspread for it's macro capability. Would modules installed in my venv be available to the spreadsheet programs? Thanks, Jim [1] https://realpython.com/blog/python/python-virtual-environments-a-primer/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
