python3-idle from systemsmanagement:Ardana:9:CentOS:7.5 project
Select Your Operating System
Add repository and install manually
For CentOS 7.5 run the following as root:
cd /etc/yum.repos.d/ wget https://download.opensuse.org/repositories/systemsmanagement:Ardana:9:CentOS:7.5/CentOS_7.5/systemsmanagement:Ardana:9:CentOS:7.5.repo yum install python3-idle