py27-wxpython fails on Snow Leopard

After following the instructions at http://astrofrog.github.com/macports-python/ then I installed wxpython with:

sudo port install py27-wxpython

This command succeeded but did not result in an importable `wx` package:

```
mac% pythonw
Python 2.7.2 (default, Mar 5 2012, 17:39:56)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import wx
Traceback (most recent call last):
File "", line 1, in
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/wx-2.8-mac-unicode/wx/__init__.py", line 45, in
from wx._core import *
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/wx-2.8-mac-unicode/wx/_core.py", line 4, in
import _core_
ImportError: dlopen(/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/wx-2.8-mac-unicode/wx/_core_.so, 2): no suitable image found. Did find:
/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/wx-2.8-mac-unicode/wx/_core_.so: mach-o, but wrong architecture
```

I think this is the same as this thread:

http://mail.python.org/pipermail/baypiggies/2011-January/007356.html

I'm currently trying the suggested fix:

```
$ port upgrade --force --enforce-variants \
py27-wxpython python27 +universal
```

The above fix did not change the error.

What works is

$ arch -i386 /opt/local/bin/python2.7 -c 'import wx'

从 MacPorts-Python 安装说明开始，执行 `sudo port install py27-wxpython`，然后使用 Snow Leopard 上所示的 Python 命令测试 `import wx`。比较 Python 和 `wx/_core_.so` 的架构；完成的标准是确定一种受支持的安装方式，或更新说明以解释可正常工作的调用方式。

由索引模型根据 Issue 内容生成。