|
patched = {} |
|
def patch(namespace, name, value): |
""" rebind the 'name' on the 'namespace' to the 'value', |
possibly and remember the original value. Multiple |
invocations to the same namespace/name pair will |
remember a list of old values. |
""" |
nref = (namespace, name) |
orig = getattr(namespace, name) |
patched.setdefault(nref, []).append(orig) |
setattr(namespace, name, value) |
return orig |
|
def revert(namespace, name): |
""" revert to the orginal value the last patch modified. |
Raise ValueError if no such original value exists. |
""" |
nref = (namespace, name) |
if nref not in patched or not patched[nref]: |
raise ValueError, "No original value stored for %s.%s" % nref |
current = getattr(namespace, name) |
orig = patched[nref].pop() |
setattr(namespace, name, orig) |
return current |
|