useful Python code

addMethod.py

import types

def foo(self, b):
    print self._a
    print b


class X(object):
    def __init__(self):
        self._a = 10


if __name__ == "__main__":
    x = X()
    x.foo = types.MethodType(foo, x)
    x.foo(2)

with_example.py

__metaclass__ = type


class withme:
    def __init__(self, avalue):
        self.avalue=avalue

    def getvalue(self):
        return self.avalue

    def __enter__(self):
        print 'in', self.avalue
        return self

    def __exit__(self, ExceptType, ExceptObj, Traceback):
        print 'out', self.avalue
        if ExceptType is not None:
            print 'Exception: type %r obj %r\n Trace: %r' % (ExceptType, ExceptObj, Traceback)
            return False  # raise exception; return true to suppress exception
        return True  # this value is ignored if there is no exception


if __name__ == '__main__':
    with withme(3) as i, withme(4) as j:
        print i.getvalue(), j.getvalue()