1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
|
The ``futurize`` script passes Python 2 code through all the appropriate fixers
to turn it into valid Python 3 code, and then adds ``__future__`` and
``future`` package imports to re-enable compatibility with Python 2.
For example, running ``futurize`` turns this Python 2 code:
.. code-block:: python
import ConfigParser # Py2 module name
class Upper(object):
def __init__(self, iterable):
self._iter = iter(iterable)
def next(self): # Py2-style iterator interface
return next(self._iter).upper()
def __iter__(self):
return self
itr = Upper('hello')
print next(itr),
for letter in itr:
print letter, # Py2-style print statement
into this code which runs on both Py2 and Py3:
.. code-block:: python
from __future__ import print_function
from future import standard_library
standard_library.install_aliases()
from future.builtins import next
from future.builtins import object
import configparser # Py3-style import
class Upper(object):
def __init__(self, iterable):
self._iter = iter(iterable)
def __next__(self): # Py3-style iterator interface
return next(self._iter).upper()
def __iter__(self):
return self
itr = Upper('hello')
print(next(itr), end=' ') # Py3-style print function
for letter in itr:
print(letter, end=' ')
To write out all the changes to your Python files that ``futurize`` suggests,
use the ``-w`` flag.
For complex projects, it is probably best to divide the porting into two stages.
Stage 1 is for "safe" changes that modernize the code but do not break Python
2.7 compatibility or introduce a dependency on the ``future`` package. Stage 2
is to complete the process.
|
