CODEWITHSUNDEEP
python-3.xubuntupython-venv
simón
simón

Reputation: 41

Rationale for having having to install the python3-venv package

Some things you should know before I ask my question:

So, here's my problem. I was trying to create a virtual environment using venv and proceeded thusly:

According to Python's 3.5.6 venv module documentation, a virtual environment is created using the command pyvenv /path/to/new/virtual/environment. I tried that command and got:

The program 'pyvenv' is currently not installed. You can install it by typing: sudo apt install python3-venv

I then searched documentation for newer Python versions and tried the new venv command python3 -m venv /path/to/new/virtual/environment and got the following result:

The virtual environment was not created successfully because ensurepip is not available. On Debian/Ubuntu systems, you need to install the python3-venv package using the following command. apt-get install python3-venv

In both cases, the solution seems to be to install python3-venv. My question is: What exactly am I installing by installing python3-venv: Isn't venv already part of the Standard Library? Furthermore, why do I have to install it via apt-get if it is a Python module? It is my understanding that standard library modules are imported, not installed; and that modules external to the standard library are installed via pip. Related to this, why is ensurepip not available?

Second part of my question: if installing python3-venv is the way to go, what is the proper way to create a virtual environment using venv in Python 3.5.2: pyvenv my_virtual_environment or python3 -m venv my_virtual_environment?

Upvotes: 4

Views: 739

Answers (1)

nnnmmm
nnnmmm

Reputation: 8744

Don't worry about the documentation not matching the micro version number – increments in that place are only for bugfixes, so the documentation stays the same.

Your question is interesting since venv is indeed not an optional module. My guess is that the Python version shipped with your OS (or that you installed yourself) seems to come with a stripped down or no standard library. For instance, the python3.5-minimal package doesn't appear to have it. Does your Python have the other modules in the standard library?

Edit: See also this question.

Installation can be described as "putting files onto your computer, in the right place". Importing a module, however, means that you tell Python to make available some functionality. To import a module, it must be installed (e.g. in /usr/lib/python3.5 for Python 3 on my computer), and one method for installing additional modules is via apt.

The python3 -m venv my_virtual_environment method should work in 3.5 as well and is the future-proof version, so you should probably go with that.

Upvotes: 2

Related Questions