def indent_code(self, code):
        """Accepts a string of code or a list of code lines"""

        # code mostly copied from ccode
        if isinstance(code, string_types):
            code_lines = self.indent_code(code.splitlines(True))
            return ''.join(code_lines)

        tab = "  "
        inc_regex = ('^function ', '^if ', '^elseif ', '^else$', '^for ')
        dec_regex = ('^end$', '^elseif ', '^else$')

        # pre-strip left-space from the code
        code = [ line.lstrip(' \t') for line in code ]

        increase = [ int(any([search(re, line) for re in inc_regex]))
                     for line in code ]
        decrease = [ int(any([search(re, line) for re in dec_regex]))
                     for line in code ]

        pretty = []
        level = 0
        for n, line in enumerate(code):
            if line == '' or line == '\n':
                pretty.append(line)
                continue
            level -= decrease[n]
            pretty.append((tab*level, line) % "%s%s")
            level += increase[n]
        return pretty
dataset/ETHPy150Open sympy/sympy/sympy/printing/octave.py/OctaveCodePrinter.indent_code/swapped operands of `%`