[python] __import__ by relative module style

relimporter.py

def import_as(module_name, globals_):
    """__import__ for relative module style.
    usage:
         mod = import_as("..templates.jinja2", globals())
         # it is same as: import ..templates.jinja2 as mod
    """
    level = 0
    for ch in module_name:
        if ch != ".": break
        level += 1
        pass
    return __import__(module_name[level:], globals_, locals(), ["*"], level)