invalid argument "/python:3.7_1912040917" for "-t, --tag" flag: invalid reference format

[Abdelkrim]

to whom it may concern,

I receive the following error message when I run build.sh

QUESTION: any idea?

QUESTION: how to build the dockerfile?

the error message

/python/3.7 (master)
$ ./build.sh
++ date -u +%y%m%d%H%M

• buildnumber=1912040917
• docker build --no-cache -t /python:3.7_1912040917 . > invalid argument "/python:3.7_1912040917" for "-t, --tag" flag: invalid reference format
  See 'docker build --help'.`