将 Flask 设置为为每个环境单独配置时的非现有路径

Question

我为每个环境和一个单独的应用程序分别配置了 目录树如下所示：

myapp
├── __init__.py         # empty
├── config
│   ├── __init__.py     # empty
│   ├── development.py
│   ├── default.py
│   └── production.py
├── instance
│   └── config.py
└── myapp
   ├── __init__.py
   └── myapp.py

代码

相关代码，myapp/__init__.py：

from flask import Flask

app = Flask(__name__, instance_relative_config=True)
app.config.from_object('config.default')
app.config.from_pyfile('config.py')
app.config.from_envvar('APP_CONFIG_FILE')

myapp/myapp.py:

from myapp import app
# ...

命令

然后我设置变量：

$export FLASK_APP=myapp.py

并尝试从项目根目录 运行 开发服务器：

$ flask run
Usage: flask run [OPTIONS]

Error: The file/path provided (myapp.py) does not appear to exist.  Please verify the path is correct.  If app is not on PYTHONPATH, ensure the extension is .py

并且来自项目 myapp 文件夹：

$ cd myapp
$ flask run
Usage: flask run [OPTIONS]

Error: The file/path provided (myapp.myapp.myapp) does not appear to exist.  Please verify the path is correct.  If app is not on PYTHONPATH, ensure the extension is .py

与另一个 FLASK_APP 变量：

$ export FLASK_APP=myapp/myapp.py
# in project root
$ flask run
Usage: flask run [OPTIONS]

Error: The file/path provided (myapp.myapp.myapp) does not appear to exist.  Please verify the path is correct.  If app is not on PYTHONPATH, ensure the extension is .py
# moving to project/myapp
$ cd myapp
$ flask run
Usage: flask run [OPTIONS]

Error: The file/path provided (myapp/myapp.py) does not appear to exist.  Please verify the path is correct.  If app is not on PYTHONPATH, ensure the extension is .py

其他测试未成功

$ python -c 'import myapp; print(myapp)'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/user/myapp/myapp/__init__.py", line 6, in <module>
    app.config.from_envvar('APP_CONFIG_FILE')
  File "/home/user/.virtualenvs/myapp/lib/python3.5/site-packages/flask/config.py", line 108, in from_envvar
    variable_name)
RuntimeError: The environment variable 'APP_CONFIG_FILE' is not set and as such configuration could not be loaded.  Set this variable and make it point to a configuration file

$ export APP_CONFIG_FILE="/home/user/myapp/config/development.py"
$ python -c 'import myapp; print(myapp)'<module 'myapp' from '/home/user/myapp/myapp/__init__.py'>
$ flask run
Usage: flask run [OPTIONS]
Error: The file/path provided (myapp.myapp) does not appear to exist.  Please verify the path is correct.  If app is not on PYTHONPATH, ensure the extension is .py

备注：

• 我没有使用 PYTHON_PATH 变量，它是空的

• 我已经看过其他相关问题 (Flask: How to manage different environment databases?) 但我的问题是（相对较新的）flask 命令

• 使用Python 3.5.2+

Answer 1

我花了一段时间终于找到了：

1. Flask 不喜欢在根级别具有 __init__.py 的项目，请删除 myapp/__init__.py。这是位于根文件夹中的那个：

   myapp
   ├── __init__.py     <--- DELETE
   ...
   └── myapp
       ├── __init__.py  <--- keep
       └── myapp.py
   

2. 使用$ export FLASK_APP=myapp/myapp.py

3. 指定配置的环境变量应该是它的绝对路径：export APP_CONFIG_FILE="/home/user/myapp/config/development.py"

现在一切正常\o/

$ flask run
* Serving Flask app "myapp.myapp"
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

$ flask shell
Python 3.5.2+ (default, Sep 22 2016, 12:18:14) 
[GCC 6.2.0 20160927] on linux
App: myapp
Instance: /home/user/myapp/instance
>>>