When trying to install pymssql with pip you may get a requirements error for libgnutls.so.26
To fix this error I took the following steps:
For the below you may need the EPEL repo, install this with the below command
yum install epel-release
Install gcc
yum install gcc
Install python-devel
yum install python-devel
Download freetds-devel
and freetds
for CentOS 7 and store in /tmp/
(or somewhere else, but remember where you stored it for later)
Install both of them
yum install /tmp/freetds-0.95.19-1.el7.x86_64.rpm
yum install /tmp/freetds-devel-0.95.19-1.el7.x86_64.rpm
Run pip install pymssql
again, it should hopefully succeed this time.