def create_table(self, name, schema):
        """
        Create a new table.

        If the table already exists, nothing happens.

        Example:

            >>> db.create_table("foo", (("id", "integer primary key"),
                                        ("value", "text")))

        Arguments:

           name (str): The name of the table to create.
           schema (sequence of tuples): A list of (name, type) tuples
             representing each of the columns.
        """
        columns = [" ".join(column) for column in schema]
        self.execute("CREATE TABLE IF NOT EXISTS {name} ({columns})"
                     .format(name=name, columns=",".join(columns)))