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Diffstat (limited to 'docs')
| -rwxr-xr-x | docs/topics/migrations.txt | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/docs/topics/migrations.txt b/docs/topics/migrations.txt index 238a600caf..41ad9e3db4 100755 --- a/docs/topics/migrations.txt +++ b/docs/topics/migrations.txt @@ -638,6 +638,26 @@ The decorator adds logic to capture and preserve the arguments on their way into your constructor, and then returns those arguments exactly when deconstruct() is called. +Supporting Python 2 and 3 +------------------------- + +In order to generate migrations that support both Python 2 and 3, all string +literals used in your models and fields (e.g. ``verbose_name``, +``related_name``, etc.), must be consistently either bytestrings or text +(unicode) strings in both Python 2 and 3 (rather than bytes in Python 2 and +text in Python 3, the default situation for unmarked string literals.) +Otherwise running :djadmin:`makemigrations` under Python 3 will generate +spurious new migrations to convert all these string attributes to text. + +The easiest way to achieve this is to follow the advice in Django's +:doc:`Python 3 porting guide </topics/python3>` and make sure that all your +modules begin with ``from __future__ import unicode_literals``, so that all +unmarked string literals are always unicode, regardless of Python version. When +you add this to an app with existing migrations generated on Python 2, your +next run of :djadmin:`makemigrations` on Python 3 will likely generate many +changes as it converts all the bytestring attributes to text strings; this is +normal and should only happen once. + .. _upgrading-from-south: Upgrading from South |