从 wsgi 导入 python 失败答案

【问题标题】：Import python from wsgi fails从 wsgi 导入 python 失败
【发布时间】：2013-03-15 08:12:50
【问题描述】：

我在 apache2/flask 服务器上有一个文件夹结构：

/var/www/myapp
/var/www/myapp/routing.py
/var/www/myapp/__init__.py
/var/www/wsgi-scripts/myapp.wsgi

我的应用文件（routing.py）在myapp中，如下：

from flask import Flask, render_template
app = Flask(__name__)


@app.route('/')
def welkom():
    return render_template('welkom.html')


if __name__ == '__main__':
    app.debug = 'True'
    app.run()

我在 wsgi-scripts 中的 myapp.wsgi 是这样的：

import sys
sys.path.insert(0, '/var/www/myapp')
from myapp import routing as application

但是，当我加载页面时，这是在我的日志中：

[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11] mod_wsgi (pid=23574): Target WSGI script '/var/www/wsgi-scripts/myapp.wsgi' cannot be loaded as Python module.
[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11] mod_wsgi (pid=23574): Exception occurred processing WSGI script '/var/www/wsgi-scripts/myapp.wsgi'.
[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11] Traceback (most recent call last):
[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11]   File "/var/www/wsgi-scripts/myapp.wsgi", line 3, in <module>
[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11]     import myapp.routing as application
[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11] ImportError: No module named myapp.routing
[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11] mod_wsgi (pid=23575): Target WSGI script '/var/www/wsgi-scripts/myapp.wsgi' cannot be loaded as Python module.
[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11] mod_wsgi (pid=23575): Exception occurred processing WSGI script '/var/www/wsgi-scripts/myapp.wsgi'.
[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11] Traceback (most recent call last):
[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11]   File "/var/www/wsgi-scripts/myapp.wsgi", line 3, in <module>
[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11]     import myapp.routing as application
[Fri Mar 15 08:06:32 2013] [error] [client 192.168.1.11] ImportError: No module named myapp.routing
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11] mod_wsgi (pid=23577): Target WSGI script '/var/www/wsgi-scripts/myapp.wsgi' cannot be loaded as Python module.
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11] mod_wsgi (pid=23577): Exception occurred processing WSGI script '/var/www/wsgi-scripts/myapp.wsgi'.
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11] Traceback (most recent call last):
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11]   File "/var/www/wsgi-scripts/myapp.wsgi", line 3, in <module>
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11]     import myapp.routing as application
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11] ImportError: No module named myapp.routing
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11] mod_wsgi (pid=23573): Target WSGI script '/var/www/wsgi-scripts/myapp.wsgi' cannot be loaded as Python module.
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11] mod_wsgi (pid=23573): Exception occurred processing WSGI script '/var/www/wsgi-scripts/myapp.wsgi'.
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11] Traceback (most recent call last):
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11]   File "/var/www/wsgi-scripts/myapp.wsgi", line 3, in <module>
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11]     import myapp.routing as application
[Fri Mar 15 08:06:33 2013] [error] [client 192.168.1.11] ImportError: No module named myapp.routing

WSGI 工作正常，我通过 testapp 验证了这一点。出了什么问题？

【问题讨论】：

我相信你的文件应该是__init__.py而不是init.py，你的路径应该是/var/www/。或者你仍然可以使用/var/www/myapp/（忘记关于__init__.py的部分），但你必须只导入routing。

标签： python apache2 flask mod-wsgi

【解决方案1】：

所以你打算从包myapp 中导入一个模块routing 并将其命名为application。

这与您的结构不匹配。如果路径中有/var/www/myapp，则必须直接导入模块routing。
应用程序不是模块，它是模块中定义的可调用对象。看来你必须做类似的事情
```
def theapp(<don't remember the argumets by heart>):
    app.debug = 'True'
    app.run()
```
然后wsgi脚本就可以了
```
from routing import theapp as application
```
但也许我在这里错了，你只需要这样做
```
from routing import app as application
```
因为我没有使用 Flask 的经验。

【讨论】：

【解决方案2】：

我遇到了同样的问题，用下面的 sn-p 解决了：

ALLDIRS = ['/var/www/MarkerDB/']

import sys 
import site 

# Remember original sys.path.
prev_sys_path = list(sys.path) 

# Add each new site-packages directory.
for directory in ALLDIRS:
  site.addsitedir(directory)

# Reorder sys.path so new directories at the front.
new_sys_path = [] 
for item in list(sys.path): 
    if item not in prev_sys_path: 
        new_sys_path.append(item) 
        sys.path.remove(item) 
sys.path[:0] = new_sys_pat

来源：http://code.google.com/p/modwsgi/wiki/VirtualEnvironments#Application_Environments

【讨论】：