Posting despite the fact this is an old topic, given it is a popular hit when searching for this.
Posted at https://www.reddit.com/r/TOR/comments/d8td66/quickdirty_installation_guide_for_installing_nyx/ as well.
TL;DR: pip3.x is probably the easiest way for CentOS/RHEL7.
* A functioning tor node
ControlPort 9051 and
CookieAuthentication 1 in your
Step 1: Install Extra Packages for Enterprise Linux (EPEL) repository configuration
sudo yum -y install epel-release
Step 2: Install python34-setuptools
sudo yum -y install python34-setuptools
Step 3: Install pip
sudo easy_install-3.4 pip
Step 4: Install nyx itself
sudo pip3.7 install nyx
Step 5: Enjoy
nyx will run as root but there is no benefit to doing so and you probably should practice not running things as root for the lols.