def get_price(self, undefined=""):
        """
        Args:
            undefined (optional): Argument, which will be returned if the
                      `price` record is not found.

        Returns:
            str: Price of the book (with currency) or `undefined` if `price` \
                 is not found.
        """
        return _undefined_pattern(
            "".join(self.get_subfields("020", "c")),
            lambda x: x.strip() == "",
            undefined
        )
def get_price(self, undefined=""):
        """
        Args:
            undefined (optional): Argument, which will be returned if the
                      `price` record is not found.

        Returns:
            str: Price of the book (with currency) or `undefined` if `price` \
                 is not found.
        """
        return _undefined_pattern(
            "".join(self.get_subfields("020", "c")),
            lambda x: x.strip() == "",
            undefined
        )
def get_price ( self , undefined = "" ) : return _undefined_pattern ( "" . join ( self . get_subfields ( "020" , "c" ) ) , lambda x : x . strip ( ) == "" , undefined )
Args:
            undefined (optional): Argument, which will be returned if the
                      `price` record is not found.

        Returns:
            str: Price of the book (with currency) or `undefined` if `price` \
                 is not found.
Args : undefined ( optional ) : Argument which will be returned if the price record is not found .