python在virtual environment (venv) 環境時，vscode pylint會報import ... not found

在python的virtual environment工作時，vscode的pylint會說找不到套件，
因此我們要vscode的「Folder Settings」去指定 venv 下的pylint路徑，而不是global的pylint，
順便把python路徑也一起修改：

(Windows)
"python.pythonPath": "${workspaceFolder}/Scripts/python.exe"
"python.linting.pylintPath": "${workspaceFolder}/Scripts/pylint.exe"

(Linux)
"python.pythonPath": "${workspaceFolder}/bin/python"
"python.linting.pylintPath": "${workspaceFolder}/bin/pylint"


因外由於 pylint 對 python 3.7的支援性不太好(沒事就在噴runtime error錯誤)，
我們可以安裝 preview version的pylint來解決：

pip install pylint astroid --pre -U

或改用flake8也行：
pip install flake8

用flake8記得修改vscode設定：
"python.linting.flake8Enabled": true
"python.linting.pylintEnabled": false
"files.trimTrailingWhitespace": true

Python CGI on Apache & FASTCGI on NginX

在Apache2上修改http.conf，讓Apache能以CGI執行python:
==============================================
...
LoadModule cgid_module modules/mod_cgid.so
...
<Directory "/opt/bitnami/apache2/htdocs">
...
Options FollowSymLinks MultiViews +ExecCGI
AddHandler cgi-script .py
...
</Directory>
==========================================================
若是使用bitnami LAMP stack，需再同時修改 conf/bitnami/bitnami.conf，修改設定同上
==========================================================

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

==========================================================
在NginX上修改nginx.conf，加入以下片段，以fast-cgi執行python:
==========================================================
location ~ \.py$ {
    root html;
    fastcgi_read_timeout 300;
    #fastcgi_pass 127.0.0.1:10240;
    fastcgi_pass unix:/tmp/python-fcgi.sock; #使用.sock監聽
    fastcgi_index index.py;
    fastcgi_param SCRIPT_FILENAME $request_filename;
    include fastcgi_params;
}
==========================================================
若是使用bitnami，可以新建一個 conf/bitnami/pythonfastcgi.conf，加入如上設定，並修改 conf/bitnami.conf，加入：

include "/Applications/nginxstack-1.10.1-2/nginx/conf/bitnami/pythonfastcgi.conf";
==========================================================
然後python需安裝flup，用來當做fastcgi的gateway(即符合fastcgi協定的SERVER，這樣才能溝通):
pip3 install flup

然後寫一支 wsgi.py，並啟動(以/tmp/python-fcgi.sock監聽)：
==========================================================
#!/usr/local/bin/python3
#coding=utf-8

from html import escape
import sys, os
from flup.server.fcgi import WSGIServer

def app(environ, start_response):
    start_response('200 OK', [('Content-Type', 'text/html')])
    yield '<h1>FastCGI Environment</h1>'
    yield '<table>'
    for k, v in sorted(environ.items()):
        yield '<tr><th>%s</th><td>%s</td></tr>' % (escape(k), escape(v))
    yield '</table>'

if __name__ == '__main__':
    # WSGIServer(app, bindAddress=('127.0.0.1',10240)).run()
    WSGIServer(app, bindAddress='/tmp/python-fcgi.sock').run()
==========================================================
修改為執行檔並執行，再執行nginx:
chmod +x wsgi.py
./wsgi.py
systemctl start nginx

uWSGI是一個軟體專案名稱，而flup本身就是一個架構在uWSGI專案之上的server，同時支援了：
wsgi-->可支援fastcgi
uwsgi-->python web server protocol
http協定
等，因此Nginx也可以改用uwsgi(設定uwsgi_pass)去執行，可參考下面最後一個鏈結

ref:
https://httpd.apache.org/mod_fcgid/mod/mod_fcgid.html
https://httpd.apache.org/docs/2.4/howto/cgi.html
http://uwsgi-docs.readthedocs.io/en/latest/WebServers.html
https://segmentfault.com/a/1190000003993249
https://www.digitalocean.com/community/tutorials/how-to-serve-flask-applications-with-uwsgi-and-nginx-on-ubuntu-14-04