Python Cheat Sheet

Python Cheat Sheet

Connect to Microsoft SQL Server Using PHP

Connect to Microsoft SQL Server Using PHP

Below Code will connect to the Microsoft Sql Server using php script.

Authenticating with OAuth 2.0 For LinkedIn Api Access using PHP

Authenticating with OAuth 2.0 For LinkedIn Api Access using PHP

LinkedIn Oauth 2.0 PHP Access

Follow these steps to enable your application to make
authenticated API calls to LinkedIn using OAuth 2.0:

Step 1: Configuring your LinkedIn application.

Create application in linkedin Developers Panel Link.

After Clicking on Create App. Fill the form information.

Once you save your configuration, your application will be assigned a unique "Client ID"   and "Client Secret" value.


Step2: Using the below PHP code to get the LinkedIn access Token to access there apis

Reading Excel Spreadsheets with Python

Excel & Python

Reading an Excel Spreadsheet

In this section, we will look at a function that demonstrates reads the Excel sheet data and convert that data into XML file.

We Used the following libraries to do the above functionality

• Openpyxl : Openpyxl is a Python library for reading and writing Excel 2010 xlsx/xlsm/xltx/xltm files.
• xml.etree.ElementTree: To create the xml tree elements
• datetime: to conver the date time column values to specified format 

PHP popen() Function

popen in php

Parallel processing in PHP Using popen() Function

Since PHP does not offer native threads, we have to get creative to do parallel processing.

There will be scenarios where PHP takes much time to complete a task. Example scenarios are attaching a large file and and sending an email, or processing a large video file 

to make thumbnails. Imagine  a user having to wait until PHP finishes the all that job.

All the heavy work might being going on at the server. 

But, if a user doesn't see any activity on a page for some time, they might think that the page is not working and leave the page.  In such cases, we can make use of a background process.

Example of popen as a Async processing

Make popen as synchronous

The below code will wait until child process completed.

echo date("h:i:s");echo "\n";
$ph = popen('php ' . $commandName , 'r') or die($php_errormsg);
while (! feof($ph)) {
$s = fgets($ph) or die($php_errormsg);
}
pclose($ph) or die($php_errormsg);
echo date("h:i:s");echo "\n";

Install mysql-python in windows

To Enable the mysql extension related python need to run the below command

pip install mysqlclient

If you are trying to use mysqlclient on WINDOWS with this failure,

   "_mysql.c(29) : fatal error C1083: Cannot open include file: 'my_config.h': N
 such file or directory"

try to install the lower version instead:

pip install mysqlclient==1.3.4

Configure Apache web server for Python on Windows

Run Python script as CGI program with Apache2.4 in Windows

1. Install Python and Apache

Python: http://python.org/download/.

Apache: http://httpd.apache.org/download.cgi


2. Configure Apache to run Python CGI

The next step is to edit ‘httpd.conf’ apache configuration file located in the apache
install directory in the conf directory.

Uncomment the below line
#LoadModule cgi_module modules/mod_cgi.so

After Uncomment
LoadModule cgi_module modules/mod_cgi.so

Search the httpd.conf file for the line

Options Indexes FollowSymLinks

Add ExecCGI to the end of the line. After adding total line looks like below

Options Indexes FollowSymLinks ExecCGI

Next, search for the following:

#AddHandler cgi-script .cgi

Uncomment this line by removing the # in front of the line,
and add a .py to the end of the line. The new line should look like this:


 AddHandler cgi-script .cgi .py



Search for the line: ScriptAlias /cgi-bin/ /whatever-path/ – when you find it,
comment out the line: that is add a # in front of the line:
(or)Other wise add the below line

ScriptAlias /cgi-bin/ "C:/Apache2.4/cgi-bin/"


3. Restart Apache


4. Run the sample python file

Here is an example assuming Python is installed in the C:\Python27 location



Save this file as test.py to your htdocs folder under your apache installation directory.
Open your web browser and type in your apache host
(and :port if the port is something other than 80) followed by test.py,
for example:   http://localhost/test.py

PHP Array insert, delete, view operation using php array functions

PHP Array Functions

Insert the array element, View the array values and delete the array value using php array functions

Function Name	Description
array_search()	Searches an array for a given value and returns the key
array_splice()	Removes and replaces specified elements of an array

Sample php array functions code

Asterisk Call Originate Action Using Pami

asterisk

What is Asterisk?

Asterisk is an open source framework for building communications applications. Asterisk turns an ordinary computer into a communications server. Asterisk powers IP PBX systems, VoIP gateways, conference servers and other custom solutions. It is used by small businesses, large businesses, call centers, carriers and government agencies, worldwide. Asterisk is free and open source.

About PAMI

PAMI means PHP Asterisk Manager Interface. It is an OOP client for the Asterisk Manager Protocol, implemented in PHP.

About PAMI Features

• TCP and TLS connections.
• Event Driven (the framework will dispatch events to your listener).
• Lightweight, easy of use, and useful.
• Supports synchronous and asynchronous events (Actions with Responses, and 
• Responses with Events associated).
• Supports SMS via VGMS boards.

Getting Started with Redis in PHP

What is Redis?

Redis created by Salvatore Sanfilippo is an open source, in-memory data structure server with advanced key-value cache and store, often referred to as a NoSQL database. It is also referred to as a data structure server, since it can store strings, hashes, lists, sets, sorted sets, and more.

The essence of a key-value store is the ability to store some data, called a value inside a key. This data can later be retrieved only if we know the exact key used to store it.

Usage of Redis

• Caching can be used in the same manner as memcached.
• Leaderboards or related problems.
• Counting stuff.
• Real time analysis.
• Deletion and filtering.
• Show latest item listings in your home page.

Install on Windows

Now, let us check how to set up Redis PHP driver.

You need to download the phpredis from github repository https://github.com/nicolasff/phpredis. Once you’ve downloaded it, extract the files to phpredis directory.

extension = redis.so

Connect to Redis Server

Inter Process Communication Using PHP ,ZeroMQ AND React/ZMQ

push the external changes to existing web pages

The above diagram shows the any external php file or database layer changes has happen should be notify to all our web client. We can able to achieve this using React/ZMQ

Requirements

ZeroMQ

All Our client web pages will be listening to port 8080 for incoming WebSocket connections...but how will it also get updates from another PHP script or another server process event. Enter ZeroMQ. We could use raw sockets, like the ones Ratchet is built on, but ZeroMQ is a library that just makes sockets easier. install zmq

React/ZMQ

Ratchet is a WebSocket library built on top of a socket library called React. React handles connections and the raw I/O for Ratchet. In addition to React, which comes with Ratchet, we need another library that is part of the React suite: React/ZMQ. This library will bind ZeroMQ sockets to the Reactor core enabling us to handle both WebSockets and ZeroMQ sockets. To install, your composer.json file should look like this:

To Run the above application go to root directory "push" run below command to run the web socket connection on server side

php bin/push-server.php

Run the : "push\src\MyApp\clientwebpage.html" which connect to web socket listen to the specified category

PHP ZMQ extension Installation in Apache 2.4 & php 5.6

PHP ZMQ extension we will look at how you can easily distribute work to background processes, provide flexible service brokering for your next service oriented architecture, and manage caches efficiently and easily with just PHP and the ZeroMQ libraries. Whether the problem is asynchronous communication, message distribution, process management or just about anything, ZeroMQ can help you build an architecture that is more resilient, more scalable and more flexible, without introducing unnecessary overhead or requiring a heavyweight queue manager node..

Installing ZMQ in Windows

Required Softwares Apache 2.4 & PHP 5.6

1. Download the zmq php extension from following url depends up on the installed php version
   url: ZMq Download Url
2. Extract the folder
3. Copy the php_zmq.dll to php/ext directory
4. Then copy the libzmq.dll to the php/ root directory
5. Add below line in php.ini file : extension=php_zmq.dll

Defining a HTML template to append using JQuery

Append Dynamic content to html template using Jquery

If we want to append the dynamic content to html template using jquery below will be the simple solution

Iframe communication or Accessing a cross-origin frame

Accessing a cross-origin frame.

window.postMessage allows you to send messages not only across frames (regular frame or iframe) but also across domains. This post showed interaction from parent to child. Even when we keep the iframe domain url is different for the main page url.
With out using the window.postMessage will gives us below error message in console

SecurityError: Blocked a frame with origin from accessing a cross-origin frame

You can't access an iframe with Javascript, it would be a huge security flaw if you could do it.
For the same-origin policy browsers block scripts trying to access a frame with a different origin.
Origin is considered different if at least one of the following parts of the address isn't maintained: ://:/path/to/page.html Protocol, hostname and port must be the same of your domain, if you want to access a frame.


Examples
Here's what would happen trying to access the following URLs from http://www.example.com/home/index.html

URL RESULT
http://www.example.com/home/other.html -> Success
http://www.example.com/dir/inner/another.php -> Success
http://www.example.com:80 -> Success (default port for HTTP)
http://www.example.com:2251 -> Failure: different port
http://data.example.com/dir/other.html -> Failure: different hostname
https://www.example.com/home/index.html.html -> Failure: different protocol
ftp://www.example.com:21 -> Failure: different protocol & port
https://google.com/search?q=james+bond -> Failure: different hostname & protocol
Workaround

Get Google contacts with Javascript using Google Contacts API and OAUTH 2.0

To get the Google Contacts with Javascript using Google Contacts Api

To Pull the google contacts we need to create a project in google developer console

Create a Google application in Google Developers Console for obtaining your Client id and Client secret

• Go to Google Google Developers Console and login with your google account.
• create one a project by clicking Create Project Button
• 
• Go into the newly created project
• Click On the Menu icon and select the Api Manager Link
• 
• Search for “Contacts API” and click on it
• 
• Enable the “Contacts API” by hitting the “Enable API” button
• 
• 

Below is the code to pull the contacts from google relplace client id with newly created client id

Deploy files or directory hierarchies to a server using Grunt and ppk file

Grunt Sftp Deployment using ppk file

Add Grunt sftp-deploy plugin using below command

npm install grunt-sftp-deploy

Create the Gruntfile.js

Create the .ftppass The below file will contains the server connection details

With any luck, you will get a sweet deployment result like this after enter the below command

$ grunt sftp-deploy:build
>> Logging in with key at E:/credentials/keys/serverkey.ppk
>> Concurrency : 4
transferred=[1/3] elapsed=[0.0s] overall=[33%] eta=[0.0s] [====== ]
>> Directories done.
transferred=[2/3] elapsed=[0.7s] overall=[67%] eta=[0.4s] [============ ]
>> Transferred : 0 Mb
Done, without errors.

GUI version control for Linux system

RabbitVCS 

TortoiseSVN alternative for Linux is RabbitVCS.  

Install RabbitVCS in Ubuntu

Sure, you can always work with SVN repositories from the command line but sometimes a graphical SVN client is more convenient - for example you can use it to check which files are not added to the repository yet. And when it comes to graphical SVN clients, I'm sure most of you will agree when I say that RabbitVCS, a "set of graphical tools written to provide simple and straightforward access to the version control systems you use" inspired by the famous TortoiseSVN, is probably the best such tool for Linux.

(RabbitVCS Gedit plugin)

Not just for SVN / Nautilus

RabbitVCS has most of the TortoiseSVN features and nicely integrates into the GNOME desktop thanks to a Nautilus Extension and a Gedit plugin for easy access to everything you need. Further more, even though its main page doesn't mention this, RabbitVCS is not just for Nautilus / SVN! It works with GIT (starting with version 0.14, released on January 4th, 2011) too and it also has a Thunar plugin so you can use it under XFCE too.

Those of you who haven't tried Rabbitvcs lately will be glad to know that since version 0.14.1.1 things became quite stable and Nautilus now stays responsive while the plugin checks for changes in the background. In fact, the v0.14 release cycle ended and the RabbitVCS developer posted a roadmap for the v0.15 cycle which includes: recursive/async status monitor for Nautilus, RabbitVCS menu items and emblems to the Gedit file browser plugin and refactor VCS abstraction code to make it easier to add new VCSs and UIs. He needs some help with all this so if you can, help him out!

Install RabbitVCS in Ubuntu

1. Add the RabbitVCS Ubuntu PPA:

sudo add-apt-repository ppa:rabbitvcs/ppa && sudo apt-get update

2. Install RabbitVCS:

- For Nautilus 2:

sudo apt-get install rabbitvcs-core rabbitvcs-nautilus rabbitvcs-cli

- For Nautilus 3 (Ubuntu 11.10, 12.04):

sudo apt-get install rabbitvcs-core rabbitvcs-nautilus3 rabbitvcs-cli

- For Thunar:

sudo apt-get install rabbitvcs-core rabbitvcs-cli rabbitvcs-thunar

Once installed, restart Nautilus / Thunar (for Nautilus, type "nautilus -q" in a terminal).


Optional: If you also want to install the RabbitVCS Gedit extension, use the following command:

sudo apt-get install rabbitvcs-gedit

Check Mod Rewrite Enabled or not in Apache

To check either mod rewrite enabled or not in Apache

Check mod rewrite is enabled or not

1. Create sample.php file in localhost root folder with below content

print_r(apache_get_modules());

output check for mod_rewrite

2.To check .htaccess is working keep the below code in .htaccess

RewriteEngine On
RewriteRule ^.*$ test.php 

REMOTE DEBUGGING ON IOS for Ios APACHE CORDOVA and mobile webpages

Safari Remote Debug Tool

This tutorial will show you how to remotely debug your cordova app on iOS using the safari remote debug tool to inspect the java script errors .

Enable Debugging on Desktop side

First, you need to enable Safari Develop menu in Safari desktop. 

Go to Safari > Preferences and ensure the Show Develop menu in menu bar check box is checked.

Enable Debug Mode on Mobile

Now, you need to enable Web Inspector in the advanced Safari Settings of your iOS Device. Go to Settings > Safari > Advanced and enable Web Inspector.

Inspect with Safari


Now we're finally able to remotely debug our cordova webview with Safari. First, launch your app on your iOS device connected to the computer via USB. 

In Safari desktop, Go to Develop > Your iPad/iPhone > Index.html.

That's it! Now you should be able to debug your app like any other website!


Debug JavaScript Step by Step

Exactly like you would do on any website, you can remotely debug step by step your JavaScript code in the Safari Web Inspector.

Firebase cloud messaging Push Notification for Websites (fcm)

Getting a Configuration File

FCM FLOW

• Go to firebase console and create a new project.

• Now put your app name and select your country.

• Now click on Add Firebase to Your Android App.
• Write some code for registering the service worker
• index.html 
• this file is responsible to subscribe the user devices and sends the device tokens to server.

include below js file: https://www.gstatic.com/firebasejs/3.6.2/firebase.js add below script code in script tag:

 var config = {
            apiKey: "AIzaSyDaY7_6yfeMbXIQNLgrLa3n_IqweQ",
                    authDomain: "push-a1eaa.firebaseapp.com",
                    databaseURL: "https://push-a1eaa.firebaseio.com",
                    storageBucket: "push-a3eaa.appspot.com",
                    messagingSenderId: "3490973264967"
            };
            firebase.initializeApp(config);
             
 


            const messaging = firebase.messaging();
            messaging.requestPermission()
                    .then(function () {
                    console.log('Have permission');
                    return messaging.getToken();
                    })
                    .then(function (token) {
                    document.getElementById("bigone").innerHTML = token;
                    console.log(token);
                    })
                    .catch(function (err) {
                    console.log('Unable to get permission to notify.', err);
                    });


            messaging.onMessage(function (payload) {
            
            console.log("Message received. ", payload);
            });
 

• firebase-messaging-sw.js
  include two files : https://www.gstatic.com/firebasejs/3.5.2/firebase-app.js https://www.gstatic.com/firebasejs/3.5.2/firebase-messaging.js
  

  // Initialize the Firebase app in the service worker by passing in the
  // messagingSenderId.
  firebase.initializeApp({
    'messagingSenderId': '3490973264967'
  });
  
  // Retrieve an instance of Firebase Messaging so that it can handle background
  // messages.
  const messaging = firebase.messaging();
   
  
  // If you would like to customize notifications that are received in the
  // background (Web app is closed or not in browser focus) then you should
  // implement this optional method.
  // [START background_handler]
  messaging.setBackgroundMessageHandler(function(payload) {
    console.log('[firebase-messaging-sw.js] Received background message ', payload);
    // Customize notification here
    const notificationTitle = payload.notification.title;
    const notificationOptions = {
      body: payload.notification.body,
      
    };
  
    return self.registration.showNotification(notificationTitle,
        notificationOptions);
  });
  

• this file is responsible to receive the messages from fcm and shows the notification information
• Send Push notifications to client
• Curl request on the server side:   

  curl "https://fcm.googleapis.com/fcm/send" --request POST --header "Authorization: key=server_key" --header "Content-Type: application/json" -d "{\"to\":\"client_token\"}"
  

  Example: URL:fcm.googleapis.com/fcm/send
  method: POST
  Authorization:key=AIzaSyDJK8dkx_7-7RdJ3YsIg_ueGFnPgOGQD0k
  {
  "notification": {
  "title": "Portugal vs. Denmark",
  "body": "5 to 1",
  "icon": "firebase-icon.png",
  "click_action": "http://localhost:8081"
  },
  "registration_ids":["eBdhRIGunJk:APA91bFVvA9XMJoXrKrgvY57wiY4tIsYJFLjW5AjgZOIZ-dRDIDxkM87eCEokvRW9jk01kyFN-
  ypGYTQ_PymwbAglwS00tQqrKiG1ex29V_Uplje7dbqV988MuyifJ1zBAesHGI0vger","coWde0lMz-Q:APA91bFZB9MRqO04ZOfk80VV8WAnmDng7_NPTPDGP2Bi0PbVhPPOT-
  Nr7vfmLiDDLA1N9Y-wAYv0pGDgKImKoN1uVgCQ_2uAfVexo0wM8UEs7tY8UNNXnZjSdzEK67XSlB8o6TIZQs0G"]
  }
  
• Reference youtube url  Getting Started with Firebase Cloud Messaging on the Web - Firecasts
  

Create Ftp User

How to create a FTP user with specific /dir/ 

1. mkdir /var/www/mydomain.com
2. mkdir /var/www/mydomain.com/html
3. useradd <-username>
4. passwd <-username>
5. chown –R <-username> /var/www/mydomain.com

Set the home directory of the user with the following command

usermod -d /var/www/html/ ftpuser

Add Remote Origin to local Git Repository

Steps to add local files to  new git repository

Step 1: Switch to your repository's directory

cd /path/to/your/repo

Step 2: Connect your existing repository to github

git init
git remote add origin https://kotturs@github.org/tech/tech.git
git pull origin master
git add
git commit -m "message"
git push origin master