Code review for python code, without further explanations, many issues over there, finally getting back to you with a negative response even though there are so many issues found on the CR. there is no focus. negative experience

I applied via employee referral, then i recieved a introductory phone call from the respected manager about the interview process, and he brief about company's product. Overall interview experience was so good and smooth. From Date of Apply to last round, it all the process finished around in one month. the best part was that they asked me about my preferred date and time slots, and there was about one week gap between each round of interview, which give enough time to prepare.