Is the environment Python 2 or Python 3?

[halloleo]

I start playing around with calibre-debug. When I drop into its Python REPL it looks like Python 3, but the doco indicates Python 2. Is the doco just a bit outdated or do I understand things wrongly?

[kovidgoyal]

The default calibre builds use python 2, see https://www.mobileread.com/forums/sh...d.php?t=325721

[PeterT]

Does it depend on where you've obtained calibre; official web site vs repository?

[kovidgoyal]

All official calibre releases are python 2. Once calibre 5 is released all official releases will be python 3. If you currently want a python 3 calibre, use the betas linked to in that plugin porting thread I linked to earlier.

[halloleo]

Thanks for all the responses!

I just downloaded 4.13 from the website. So ok, it's Python 2. Fair enough. But I get a strange error which feels like a Python 3 error:

Say, I write the following script:

import calibre
print calibre.__version__

Then I call

calibre-debug script.py

and get an error:

Python function terminated unexpectedly: invalid syntax (script.py, line 2)
Traceback (most recent call last):
  File "/Applications/Optional/calibre.app/Contents/Resources/Python/lib/python2.7/site.py", line 187, in main
    return run_entry_point()
  File "/Applications/Optional/calibre.app/Contents/Resources/Python/lib/python2.7/site.py", line 121, in run_entry_point
    return getattr(pmod, func)()
  File "site-packages/calibre/debug.py", line 348, in main
  File "site-packages/calibre/debug.py", line 260, in run_script
  File "/Users/toki/devel/calibre/play/script.py", line 3
    print calibre.__version__
                ^
SyntaxError: invalid syntax

But a Python3 script like

import calibre
print(calibre.__version__)

works fine. Why's that?

[kovidgoyal]

Because calibre uses from __future__ import print_function

[BetterRed]

Originally Posted by kovidgoyal

Because calibre uses from __future__ import print_function

Wish we could, from __future__ import a coronavirus vaccine.

Ah well, back to the past. In 1665/6 London had the bubonic plague and then the Great Fire, down here we had the Great Fires and then the coronavirus plague.

Stay safe

BR

[kovidgoyal]

Originally Posted by BetterRed

Wish we could, from __future__ import a coronavirus vaccine.

BR

BCG seems promising.

[halloleo]

Originally Posted by kovidgoyal

Because calibre uses from __future__ import print_function

Of course! That's it. Thanks.

[halloleo]

Originally Posted by kovidgoyal

BCG seems promising.

Well, let's not get our hopes up too much: BCG can at best help to ease (and shorten!) the infectious stage. but it is certainly not a full vaccine.

I'm hoping that individual immunity after recovery brings in the mid-to-long run herd immunity.

[kovidgoyal]

Originally Posted by halloleo

Well, let's not get our hopes up too much: BCG can at best help to ease (and shorten!) the infectious stage. but it is certainly not a full vaccine.

That should be enough to transfrm this into a relatively minor thing along the lines of regular influenza.

I'm hoping that individual immunity after recovery brings in the mid-to-long run herd immunity.

I doubt individual immunity will last very long. These types of viruses tend to mutate a lot. But would be awesome if it does ofc.

[BetterRed]

Originally Posted by kovidgoyal

BCG seems promising.

I read that as Boston Consulting Group

BR