I know this is an old question, but the maintainer has a pyodbc GitHub Repo.
I also found a very good example for installing FreeTDS and setting up the config files.
Following the instructions on the GitHub docs seems to me to always be the best option. As of February, 2018, for CentOs7 (they have all flavors at the link) they say:
# Add the RHEL 6 library for Centos-7 of MSSQL driver. Centos7 uses RHEL-6 Libraries.
sudo su
curl https://packages.microsoft.com/config/rhel/6/prod.repo > /etc/yum.repos.d/mssql-release.repo
exit
# Uninstall if already installed Unix ODBC driver
sudo yum remove unixODBC-utf16 unixODBC-utf16-devel #to avoid conflicts
# Install the msodbcsql unixODBC-utf16 unixODBC-utf16-devel driver
sudo ACCEPT_EULA=Y yum install msodbcsql
#optional: for bcp and sqlcmd
sudo ACCEPT_EULA=Y yum install mssql-tools
echo 'export PATH="$PATH:/opt/mssql-tools/bin"' >> ~/.bash_profile
echo 'export PATH="$PATH:/opt/mssql-tools/bin"' >> ~/.bashrc
source ~/.bashrc
# optional: for unixODBC development headers
sudo yum install unixODBC-devel
# the Microsoft driver expects unixODBC to be here /usr/lib64/libodbc.so.1, so add soft links to the '.so.2' files
cd /usr/lib64
sudo ln -s libodbccr.so.2 libodbccr.so.1
sudo ln -s libodbcinst.so.2 libodbcinst.so.1
sudo ln -s libodbc.so.2 libodbc.so.1
# Set the path for unixODBC
export ODBCINI=/usr/local/etc/odbc.ini
export ODBCSYSINI=/usr/local/etc
source ~/.bashrc
# Prepare a temp file for defining the DSN to your database server
vi /home/user/odbcadd.txt
[MyMSSQLServer]
Driver = ODBC Driver 13 for SQL Server
Description = My MS SQL Server
Trace = No
Server = 10.100.1.10
# register the SQL Server database DSN information in /etc/odbc.ini
sudo odbcinst -i -s -f /home/user/odbcadd.txt -l
# check the DSN installation with:
odbcinst -j
cat /etc/odbc.ini
# should contain a section called [MyMSSQLServer]
# install the python driver for database connection
pip install pyodbc