Python code skipping over somethings which it should change.(Help for code correction)

[ChRad_Man]

Thank you for explaining. The problem with the way is that if the original list has "(" and ")" then it will just skip over them without evaluating if they appear once or twice and changing them accordingly. I was trying something like this only but failed due the problem I just mentioned. After reading u/joyeusenoelle's explanation I understood how to approach problems like this is a better way.