Please tell what these errors mean ?

Question

https://code.sololearn.com/ccYqnmLvAkm2/?ref=app

Answer 1

https://code.sololearn.com/clUgKc3VU5rO/?ref=app

1.invalid characters are in your code
2.{()} what? must be (())

Answer 2

you are great . thanks .

Answer 3

why opr [1] did not work . I have used it in many codes .