lib2to3import 2017.3.3.post2

不带lib2to3导入

>>> from py2codes import py2_print
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "py2codes/py2_print.py", line 1
    print "Written when Python 2 was majority."
                                              ^
SyntaxError: Missing parentheses in call to 'print'

使用lib2to3import

>>> from lib2to3import import lib2to3importer, prepending
>>> fixers = ["lib2to3.fixes.fix_print"]
>>> with prepending(lib2to3importer(fixers, "py2codes.")):
...     from py2codes import py2_print
...
Written when Python 2 was majority.

限制

无法同时对两个不同的根应用修复。

当您同时对“foo.module”和“bar.module”应用修复程序时，您 必须省略prefix参数，它使修复应用于所有模块 以及要导入的包。

并发导入：

from lib2to3import import lib2to3importer, prepending
fixers = ["lib2to3.fixes.fix_print"]

with prepending(lib2to3importer(fixers)):
    import foo.module  #  import chain: 1. foo.module -> 2. bar.module

2步骤导入（推荐）：

from lib2to3import import lib2to3importer, prepending
fixers = ["lib2to3.fixes.fix_print"]

with prepending(lib2to3importer(fixers, "bar.")):
    import bar.module  # ... 2

with prepending(lib2to3importer(fixers, "foo.")):
    import foo.module  # ... 1