def asformat(self, format):
if format is None or format == self.format:<EOL><INDENT>return self<EOL><DEDENT>else:<EOL><INDENT>return getattr(self,'<STR_LIT:to>' + format)()<EOL><DEDENT>
Return this matrix in a given sparse format

        Parameters
        ----------
        format : {string, None}
            desired sparse matrix format
                - None for no format conversion
                - "csr" for csr_matrix format
                - "csc" for csc_matrix format
                - "lil" for lil_matrix format
                - "dok" for dok_matrix format and so on