Category: Development

code, IDE, snippets and all about my nerd side

Identify your Twitter followings older that 4 months

Spring is all about cleaning, the saying goes, so why don’t apply the same principle also the the accounts I follow on Twitter? Why? Because I would like to maintain their number under 400 and because I would like to grow my very limited Python skills.

With the help of TweetPony (among the many), the task was pretty straightforward. Final result is a simple script that checks for the people I follow, verifies their last tweet date and alert me if it is older than four months.

Configure the Python environment (Ubuntu 14.04 Trusty)

I don’t want to pollute my system-wide Python installation with libraries and dependencies related to a single project, so I created a virtual environment. Still not a master on that, so forgive my errors:

apt-get install python-pip
sudo pip install virtualenv
cd %projectdir%
virtualenv build_dir
source build_dir/bin/activate

From now ongoing, all the pip commands will be execute inside the (build_dir) virtualdev, and not at system-wide level. Time to install the TweetPony library:

sudo pip install tweetpony

Once installed, I tried some examples from the GitHub repo, to check if it worked. And yes, it did (even without api key and permission, see later), but a boring console message appeared every time the script made a call to Twitter API, caused probably by the old Python 2.7.6 version or libs I was using:

InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning

In order to solve it, I installed some dev libraries required to compile some other Python libraries (again, inside the virtualenv only)

sudo apt-get install libssl-dev
sudo apt-get install libfii-dev
pip install cryptography
pip install pyopenssl ndg-httpsclient pyasn1
pip install urllib3

and added these lines of code at the beginning of the main function of the script, before any Twitter API call:

import urllib3.contrib.pyopenssl
urllib3.contrib.pyopenssl.inject_into_urllib3()

They made the trick! But, as I said, probably you may not need all of these.

The script

The script itself it’s pretty simple. I took the basic code to create the TweetPony API object from the repo’s example folder and I was able to get user’s friends_id (the account the user follows). Then, cycling thru each one, I checked the status of that friend, watching for last tweet date. Some cornercases management (like private tweets or no tweets at all) and voila’, I had all I needed.

Regarding authentication, all Twitter’s libraries require a consumer key and consumer secret to work, in addition to an OAuth access_token and access_token_secret. What made me preferred TweetPony to other libs, like tweepy or python-twitter, was that TweetPony doesn’t required anything. Test consumer key and secret are gently embedded into the lib source, while OAuth tokens are created on the fly for you and persisted over a file, .auth_data.json. To use new credentials, simply delete the file and add somewhere, at the beginning of your code, these two lines, with key and secret obtained from Twitter Dev Console:

tweetpony.CONSUMER_KEY = 'xxxx'
tweetpony.CONSUMER_SECRET = 'xxxxx'

Final consideration about Twitter API usage: there is a limit of 180 calls every 15 minutes, so I added a sleep after every check. Slow, but it worked with my 500+ followers :)
Continue reading “Identify your Twitter followings older that 4 months” →

Advanced dev tips for the Android Wear, Droidcon Turin

You first Android Wear app is finally complete. A working notification system, a couple of custom wear activities and an exciting voice input
control. Now what?
In this session, you’ll learn about some of the advanced Android Wear programming guidelines, code optimizations, useful community libraries, best UI patterns seen so far, brilliant watch faces, pitfalls to avoid and other “real world” Android Wear tips’nd tricks.

(Droidcon Turin, 9th April 2015)

The second screen world in the Google Cast era, Codemotion Rome

TVs are the biggest, most beautiful screen in people’s living rooms. Google Cast is a technology that enables true multi-screen experiences for the users. Integrating Google Cast into existing applications is simple, and we’re going to cover the SDK and resources available to make your application Cast enabled really easily. Android, iOS and Web. Possibilities? Endless: not only casting video or audio, but also games where the TV becomes the new and high-tech game board or a variety of other apps to enjoy with friends, sitting together on the couch.

(Codemotion Roma 2015)

Environmental variables, API key and secret, BuildConfig and Android Studio

You wanna create an Android app that uses Twittet APIs, so yo need an API key and an API secrets only you and your apps know. Because you need these values inside you app, it’s easy and quick to write them down directly in your source code. But when you commit this code to GitHub (or any other public repo), practically you’re telling your secret keys to entire world. Seems uncommon? Unfortunately, not so much! Same for Dropbox SDK.

One simple way to avoid this bad practice is to store your values inside an environmental variable, so only your machine knows it, then read this values in some way and inject them in your code at build time.
Let’s see how to do that using Android Studio, Gradle, and BuildConfig.

First, we need to create these environmental vars. In Linux and Mac, create or edit the file ~/.gradle/gradle.properties (pay attention to the actual Gradle User Home directory position) and add some values:

#define your secret values
TwitterConsumerKeyProp=xxxxxx66666666634333333ddddddTwitterConsumerSecretProp=3nkl3sds3skmslSDF394asdk39dmasd

Second, in your module’s build.gradle file, add these lines

apply plugin: 'com.android.application'
 
//Add these lines
def TWITTER_CONSUMER_KEY = '"' + TwitterConsumerKeyProp + '"' ?: '"Define Twitter Consumer key"';def TWITTER_CONSUMER_SECRET = '"' + TwitterConsumerSecretProp + '"' ?: '"Define Twitter Consumer secret"';
 
android.buildTypes.each { type ->
    type.buildConfigField 'String', 'TWITTER_CONSUMER_KEY', TWITTER_CONSUMER_KEY    type.buildConfigField 'String', 'TWITTER_CONSUMER_SECRET', TWITTER_CONSUMER_SECRET
}

Please note the “TwitterConsumerKeyProp” and “TwitterConsumerSecretProp” have to be the same in both Gradle settings file and Gradle build file.
Finally, to use these values in your code, filled at runtime by Gradle in the build script for you, simply use:

ConfigurationBuilder cb = new ConfigurationBuilder()
    .setDebugEnabled(BuildConfig.DEBUG)
    .setApplicationOnlyAuthEnabled(true)
    .setOAuthConsumerKey(BuildConfig.TWITTER_CONSUMER_KEY)    .setOAuthConsumerSecret(BuildConfig.TWITTER_CONSUMER_SECRET);

That’s all, then it’s up to you how to create more elaborated configurations. For example, you can have different values based on different android.buildTypes types, or the gradle settings file in a common network folder used by the entire team or…