For portmaster users:
# sh
# portmaster -o lang/python38 python37
# REINSTALL="$(pkg info -o py37-\* | awk '{printf "%s ", $2}')"
# REINSTALL="$(pkg info -o "*py37*" | awk '{printf "%s ", $2}')"
# pkg delete -f py37-\*
# pkg delete -f "*py37*"
# portmaster $REINSTALL
# REBUILD=$(pkg query -g "%n:%dn" '*' | grep py3 | grep -v py38 | cut -d : -f 1 | sort -u)
# portmaster $REBUILD