venv conflict at shell prompt

[Skaperen]

i have python 2.7.12 (not used for anything new) and 3.5.2. i am wondering what other versions i can run.

i have dabbled around with Linux Containers at the system level as opposed to black box tools like Docker (primarily for running services). this can be done with quite low overhead

one thing i wonder is how venv and pyenv deal with scripts that have coded the host interpreter path, on the hash-bang or elsewhere including my version switcher:

if bytes == str:
    import os,sys
    for p in os.environ.get('PATH','').split(':'):
        if p and os.path.exists(p+'/python3'):
            os.execvp(p+'/python3',['python3']+sys.argv)

the above code would normally be inserted into a file. i suppose it might work as a module but i suggest inserting it into the file you want to have run in python3. it's not that big.