Question

I’d like to stop the loading of a module if some modules dependencies arent on machine, how can i do that?

try:
    import lxml
except:
    print "This module requires lxml"
    # WHAT SHOULD I PUT HERE TO STOP MODULE LOADING?

class foo:
    pass

Answer 1

Raise the exception, or raise a new one:

try:
    import lxml
except:
    raise SomeError('This module requires lxml')

If you want to stop the interpreter entirely, use exit() to terminate the program.