Python 3.7

When will Python 3.7 be available on here?

3.7 is still in beta, but we're planning to get a new system image together reasonably soon; it will have updated versions of Python.

Now that 3.7 is released, when can we expect a new image?

It's on its way; we have one built and in testing, but there are quite a lot of tests we need to do before we can release it. It will definitely be in our next system update, though.

And when?..

Should be ready in ~ a week's time.

Not to be pushy, but.... Python 3.7? ;-)

Heh, good timing :-) It's been live for a little while now for newly-created accounts, and we were planning to do an official announcement on the blog tomorrow.

Adding Python 3.7 to your account does require upgrading your system image, though -- the new image is called "earlgrey" (after the previous system images, "classic" and "dangermouse"). What this means is that the pre-installed Python packages will all get upgraded, which means that any code you have that depends on them might stop working if it's not compatible with the new versions.

For previous upgrades, from classic to dangermouse, we said that all was OK if you were using a virtualenv, which (of course) removes the dependency on the pre-installed Python packages. However, this new image not only adds Python 3.7 and upgrades packages, it also upgrades the older Python versions -- for example, from the antediluvian 2.7.6 to 2.7.12, and from 3.6.0 to 3.6.6. This can break virtualenvs in some cases.

So, long story short -- we can certainly switch your account over to the new system image, but you may need to rebuild your virtualenvs afterwards if you're using them -- and you may need to update your code to handle newer pre-installed Python packages if you're not using virtualenvs.

There are more details about exactly which package versions are included in which system image on the batteries included page. And if you'd like to switch your account over to earlgrey, just drop us a line using the "Send feedback" button. (If you've read all of the above, and understand that you may have to make code/virtualenv changes, mention that you have in the feedback message as otherwise we'll respond by basically repeating all of the stuff I just said, and asking "are you sure?")

Resurrecting this somewhat: I've got all my code in virtualenvs so I got that bit covered. Rebuilding virtualenvs; is it as simple as deleting the old ones, creating new and 'pip install requirements.txt' and referencing the new ones under the web tab?