def run(self, engine, step):
"""Core method of Script file.
Exectues :func:`update` or :func:`downgrade` functions
:param engine: SQLAlchemy Engine
:param step: Operation to run
:type engine: string
:type step: int
"""
if step in ('downgrade', 'upgrade'):
op = step
elif step > 0:
op = 'upgrade'
elif step < 0:
op = 'downgrade'
else:
raise ScriptError("%d is not a valid step" % step)
funcname = base.operations[op]
script_func = self._func(funcname)
# check for old way of using engine
if not inspect.getargspec(script_func)[0]:
raise TypeError("upgrade/downgrade functions must accept engine"
" parameter (since version 0.5.4)")
script_func(engine)
def _func(self, funcname):
if not hasattr(self.module, funcname):
msg = "Function '%s' is not defined in this script"
raise ScriptError(msg % funcname)
return getattr(self.module, funcname)