ValueError: list.remove(x): x not in list

[MindyZHAOMinzhu]

ValueError: list.remove(x): x not in list

Describe your environment

• Python version:Python3
• Hardware:mac
• Jupyter notebook or not? [Y/N]:N
• Which chapter of book?:4

I work on Exercise 1 and I meet a problem.

Describe your question

From my perspective, i is in the list1 and obviously it it in the student_list, but there is error.

Describe the efforts you have spent on this issue

I have Google it but I do not find some similar problem.

[hupili]

you can print list1 and student_list before the error line. Then you can verify whether x is in or not