With Python 3 getting the continuing future of Python while Python 2 still is in effective use, you should get job designed for both major releases of Python. This guide is supposed to make it easier to figure out how far better help both Python 2 3 at the same time.
If you are looking to port an expansion component in place of pure Python signal, please read Porting Extension segments to Python 3 .
If you would like to see one key Python developer’s undertake why Python 3 has been around since, you can read Nick Coghlan’s Python 3 Q A or Brett Cannon’s exactly why Python 3 prevails.
The light ExplanationA¶
Use Pylint to help make yes you never regress on your Python 3 support ( python -m pip install pylint )
Usage caniusepython3 to discover which of the dependencies were preventing your own usage of Python 3 ( python -m pip install caniusepython3 )
As soon as your dependencies are not any much longer blocking your, use constant integration to make sure you stay appropriate for Python 2 3 (tox enables check against multiple versions of Python; python -m pip install tox )
Contemplate using optional fixed type examining to be certain your own type usage works in Python 2 3 (e.g. usage mypy to check your own keying in under both Python 2 Python 3; python -m pip install mypy ).
Notice: utilizing python -m pip apply ensures that pip you invoke may be the one set up for your Python presently used, whether it be a system-wide pip or one put in within a virtual surroundings .
DetailsA¶
A significant factor about support Python 2 3 simultaneously is you can beginning now! Whether or not the dependencies commonly promote Python 3 yet that doesn’t indicate you cannot modernize your code today to guide Python 3. the majority of variations needed to support Python 3 trigger cleaner rule utilizing newer procedures even in Python 2 code.
Another a key point usually modernizing your own Python 2 rule to in addition help Python 3 is largely computerized for you. You might have to make some API conclusion due to Python 3 clarifying text information versus digital information, the lower-level work is now mostly completed for you and therefore can at least take advantage of the automatic changes straight away.
Hold those key points planned although you read on about the details of porting the code to compliment Python 2 3 at the same time.
Decrease assistance for Python 2.6 and olderA¶
Whilst you will make Python 2.5 assist Python 3, truly less difficult if you just work with Python 2.7. If losing Python 2.5 just isn’t an option then six job assists you to supporting Python 2.5 3 simultaneously ( python -m pip install six ). Manage recognize, though, that Balinese pretty girls nearly all the jobs placed in this HOWTO will never be available to you.
If you should be capable skip Python 2.5 and older, then requisite adjustment your signal should always look and feel like idiomatic Python rule. At the worst you will have to use a purpose in place of an approach occasionally or need transfer a function instead of using a built-in one, but or else the general change ought not to think overseas to you.
But you should try to get merely promote Python 2.7. Python 2.6 has stopped being easily backed and thus is certainly not obtaining bugfixes. What this means is you’ll have to operate around any dilemmas you come across with Python 2.6. You will also discover some methods talked about in this HOWTO which do not help Python 2.6 (elizabeth.g., Pylint), which will be a little more prevalent in the future. It will probably merely end up being easier for you should you merely offer the variations of Python that you have to help.