python继承

1. 子类调用父类的方法

# 1
class SSHConnectionCache(ConnectionCache):
    def __init__(self):
        ConnectionCache.__init__(self, no_current_msg='No open connection.')


# 2
class SSHConnectionCache(ConnectionCache):
    ...
    def get_connection(self, alias_or_index=None):
        connection = super(SSHConnectionCache, self).get_connection(alias_or_index)
        if not connection:
            raise RuntimeError("Non-existing index or alias '%s'." % alias_or_index)
        return connection