Search for the package in yum , use the following command:
yum search python3 | grep devel
It will list all the available devel packages. The result will be somewhat like this
python3-cairo-devel.x86_64 : Libraries and headers for python3-cairo python3-devel.x86_64 : Libraries and header files needed for Python 3 : development python34-devel.x86_64 : Libraries and header files needed for Python 3 : development
Then you can choose the package you want to install from the list , suppose if you want to to install python3-devel , execute the following
yum install -y python3-devel.x86_64