Awhile back I had some thoughts on communication. If you’ve ever played World of Tanks Blitz you’d know that basically its a team of tanks against another team of tanks. With the pick up, fast paced nature communication is minimal at best (sometimes limited to a single “<<<<<<<<<” or “>>>>>>>>>” indicating which direction to take the offense). I found that teams that could coordinate with minimal communication, play their tank roles (scouts, mediums, heavies, and destroyers), and move fast could achieve massive overwhelming victories. Something similar is probably true in an agile/teamwork environment. Know your stuff, know your role, take opportunities, work together, succeed.


Have you ran into trouble with SSLErrors after upgrading to Python 3.6 on macOS Sierra?  For me, my first encounter was downloading the bokeh sample data (included here).

I finally got a chance to research exactly what was wrong.  Given that Python 3.5 was working on my machine and 3.6 was working on several linux machines, I thought that it could have been an issue with Python 3.6, unlikely as it may be.  After no bug fix version was released I realized that it must be my configuration.

Searching, I found one result related to this in the Python issue tracker: Issue 28150.  One answerer points out that Python on macOS no longer relies on Apple’s version of OpenSSL, instead it is shipped with a new one.  The gotcha: this new one does not have trust certificates installed.  All this is detailed in the Readme.

The Installer Readme

So, as the Python issue tracker mentioned, there is an entry in the installer readme.  Perhaps I should read these closer…

Certificate verification and OpenSSL

**NEW** This variant of Python 3.6 now includes its own private copy of OpenSSL 1.0.2.  Unlike previous releases, the deprecated Apple-supplied OpenSSL libraries are no longer used.  This also means that the trust certificates in system and user keychains managed by the Keychain Access application and the security command line utility are no longer used as defaults by the Python ssl module.  For 3.6.0, a sample command script is included in /Applications/Python 3.6 to install a curated bundle of default root certificates from the third-party certifi package (  If you choose to use certifi, you should consider subscribing to the project’s email update service to be notified when the certificate bundle is updated.

The bundled pip included with the Python 3.6 installer has its own default certificate store for verifying download connections.

Two Solutions

There are two solutions as mentioned:

  • Install the certifi package.
  • Run the download script provided with the installer – /Applications/Python 3.6/Install Certificates.command.

For myself, I ran the bundled script and everything seems to be functioning fine.  It seems more than a little odd that this was not done on installation.



Pip installs From github

Installing a package from github is fairly simple.  The following are examples of installing packages from github.


At some point, you will find yourself wanting to list a dependency in the requirements.txt file that resides on github.  This is fairly straight forward If you only plan to use it in requirements.txt (not processed for usage in  Note that I’ve specified the master branch of repo and given it a version id. and requirements.txt

Some people will process their requirements.txt files to generate the install_requires parameter for the setup function called in  This works fine until you have a repository on github.  Setup will fail to find your dependencies if your requirements.txt has a line like the one above.  To remedy this we must do two things.

  1. Parse the line to create a named python dependency for install requires. Given the file above, install_requires would equal ["repo==0.0.1"] .
  2. Specify the dependency_links argument to setup.  [""]  for this example.

An Example

This is an example of a that properly processes requirements.txt dependencies that are located on github.  It’s probably not complete, but it works for what I need.  Feel free to take and adapt.  See the repo here (python3).





I recently constructed a mini cluster consisting of 3 Raspberry Pi 3s.  I am planning on using these machines for various little projects.  I’ve installed some services on one of the nodes.  Currently that node hosts Redis and RabbitMQ instances.  I’m sure that I’ll have other services to install in the near future.  I may even use it to tinker with clustering those services.  Below are some pictures of the cluster as I was putting it together and a parts list.


I was tinkering around with replacing the print statement with the print function in a Python 2 script when I ran across this peculiar oddity.

Notice that sequence is just importing the future print function as different names in each iteration.  The oddity is that the first import fails but the third (which is exactly the same) succeeds after performing the second.

** Note: I don’t know if replacing print with the print from the futures module is a wise thing to do.  I was simply using it while trying out some code. **

Versions tested: Python 2.7.10 (OSX), Python 2.7.6 (Ubuntu 14.04).