Install Python 3.5

There are many ways to get Python on your system.

  • If you prefer the complete “batteries included” option, Anaconda Python is available for Mac, Windows or Linux.
  • On Mac, Homebrew is a great way to install Python.
  • If you just want a clean Python install and nothing else, installers from work great too.

Cadnano will run on Python 3.3, 3.4 and 3.5, but we only support 3.5. We do not support Python 2.X.

Install cadnano

pip3 install cadnano

Advanced: Building from scratch

Should the above not work for you:

  1. Let us know
  2. The requirements PyQt5 and SIP are available from Riverbank Computing Limited at:


Instructions to come.

Mac and Linux

These instructions can work 10.10 Yosemite and 10.11 El Capitan under Xcode 7.0.1 and 6.5. It has also been tested on Debian 7.9 Wheezy Please provide feedback if you have problems running this in issues.

You can run the included which will grab, build and install Qt5, SIP and PyQt5 in your python environment. It is cleanest using virtualenv and virtualenvwrapper creating a virtualenv with:

mkvirtualenv --always-copy <myvenv>
python pyqttools/

and then running the script, but you can definitely install in your system python if you run:

sudo python pyqttools/

This script only builds required parts of Qt5 and PyQt5 in the interest of time.

Manual installation of PyQt5 is fine too, but you’ll need to trouble shoot on your own

  1. Install Qt5. download the online installer
  2. Build sip and PyQt5 against this Qt5

Of course there are many ways to accomplish this feat, but needless to say OS X and Linux installs of PyQt5 can be painful for some people.