Flask 看不到 pip 安装的模块

Question

我在 Python 2.7.12/Apache 2.4/Ubuntu 16.04.1 LTS 上安装了 Flask。我一直在使用 these two tutorials to get set up. I'm not running venv or any other virtual environment (unlike this post)。运行一个简单的 Flask 应用程序运行良好（la "hello world"）。我在同一目录 (/var/www/html) 中有一个 flaskapp.wsgi 和一个 flaskapp.py。

flaskapp.wsgi

import sys
sys.path.insert(0, "/var/www/html/flaskapp")
from flaskapp import app as application

flaskapp.py

from flask import Flask
app = Flask(__name__)

@app.route('/')
def main():
    return "hello world"

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

但是当我尝试导入 Flask 基本模块集之外的模块时，例如。 httplib2（我通过 pip 安装），我收到 500 HTTP 错误。简单地将 import httplib2 添加到 flaskapp.py 会引发此错误。

查看 Apache 错误日志，我看到以下内容：

[wsgi:error] mod_wsgi (pid=22739): Target WSGI script '/var/www/html/flaskapp/flaskapp.wsgi' cannot be loaded as Python module.
[wsgi:error] mod_wsgi (pid=22739): Exception occurred processing WSGI script '/var/www/html/flaskapp/flaskapp.wsgi'.
[wsgi:error] Traceback (most recent call last):
[wsgi:error] File "/var/www/html/flaskapp/flaskapp.wsgi", line 7, in <module>
[wsgi:error] from flaskapp import app as application
[wsgi:error] File "/var/www/html/flaskapp/flaskapp.py", line 7, in <module>
[wsgi:error] import httplib2
[wsgi:error] ImportError: No module named httplib2

当我运行 python（不使用 Flask）时，我可以毫无困难地导入 httplib2。因此，出于某种原因，我的 Flask 应用程序似乎无法访问 pip 的导入。

以下是我到目前为止所做的故障排除：

我使用 __file__:

检查了 httplib2 住在哪里

>>> import httplib2
>>> httplib2.__file__
'/home/andrew/.local/lib/python2.7/site-packages/httplib2/__init__.pyc'

然后我在 Flask 应用程序中检查了 sys.path 和 pip.get_installed_distributions()：

flaskapp.py（修订）

from flask import Flask, jsonify
import pip, sys

modules = ""
for i in pip.get_installed_distributions():
    modules = modules + " " + str(i)

app = Flask(__name__)

@app.route('/')
def main():
    return jsonify({ "modules":modules, "sys.path":sys.path })

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

输出：

{
  "available_modules": " Flask 0.12 Jinja2 2.9.5 itsdangerous 0.24 Werkzeug 0.11.15 MarkupSafe 0.23 click 6.7", 
  "sys.path": [
    "/usr/share/python-wheels/lockfile-0.12.2-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/pkg_resources-0.0.0-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/retrying-1.3.3-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/requests-2.9.1-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/wheel-0.29.0-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/urllib3-1.13.1-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/ipaddress-0.0.0-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/colorama-0.3.7-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/distlib-0.2.2-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/pyparsing-2.0.3-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/packaging-16.6-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/html5lib-0.999-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/CacheControl-0.11.5-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/six-1.10.0-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/chardet-2.3.0-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/progress-1.2-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/setuptools-20.7.0-py2.py3-none-any.whl", 
    "/usr/share/python-wheels/pip-8.1.1-py2.py3-none-any.whl", 
    "/var/www/html/flaskapp", 
    "/usr/lib/python2.7", 
    "/usr/lib/python2.7/plat-x86_64-linux-gnu", 
    "/usr/lib/python2.7/lib-tk", 
    "/usr/lib/python2.7/lib-old", 
    "/usr/lib/python2.7/lib-dynload", 
    "/usr/local/lib/python2.7/dist-packages", 
    "/usr/lib/python2.7/dist-packages"
  ]
}

所以它可以看到httplib2所在的路径，以及flask所在的路径，但是可用的模块只有Flask模块。

我不确定这是否是我的 Apache 配置的问题 - 我已经查阅了一些操作指南和文档，这是我一直在使用的设置：

/etc/apache2/sites-enabled/000-default.conf

<VirtualHost *:80>

    WSGIDaemonProcess flaskapp threads=5 python-path=/var/www/html/flaskapp/flaskapp
    WSGIScriptAlias / /var/www/html/flaskapp/flaskapp.wsgi

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    <Directory  /var/www/html/flaskapp>
       WSGIProcessGroup flaskapp
       WSGIApplicationGroup %{GLOBAL}
       Require all granted
       WSGIScriptReloading On
    </Directory>

</VirtualHost>

我浏览了许多 SO 帖子，但大多数人似乎都担心 app 对 WSGI 不可见。看起来很接近，但还没有解决我的问题。如果有任何建议，我将不胜感激！

注意：我对 Python 很满意，对 Flask 比较熟悉，但对 Apache 和 WSGI 还是个新手。关于后两个主题（如果适用）的详细 [=81=] 答案确实有帮助。

Answer 1

您应该在 Apache 配置中将 ~/.local/ 添加到 python-path。

WSGIDaemonProcess flaskapp threads=5 python-path=/var/www/html/flaskapp/flaskapp:/home/andrew/.local

您还应该尝试使用虚拟环境，并在 WSGIDaemonProcess 上设置 python-home 作为环境根。

来源：http://modwsgi.readthedocs.io/en/develop/configuration-directives/WSGIDaemonProcess.html

编辑

您也可以使用 sudo 安装 httplib2，就像安装 flask 软件包一样（如 one of your links 所示）

Flask 看不到 pip 安装的模块

Flask can't see modules installed by pip

python

apache

mod-wsgi

flask

编辑