Resolved: This not working what is the reason?

Hey Ferdinand,

Thank you for reaching out.

When working in Jupyter notebook, you should execute the cells in order. You should therefore execute first the cell where the rand_walk function is defined (the first cell in your screenshot). Then, execute the second cell where you use the function.

Kind regards,

365 Hristina

Hi Ferdinand and Hristina! 
I hope you don't mind if I join the conversation.

Furthermore, I believe your code is missing a colon (:) at the end of the line containing the for statement. 

    for i in range(1, step_num): 
Hope this helps.
Best,
Ivan