Opening files in same directory as script

[Emekadavid]

The textbook I am using didn't specify this problem so I want someone to help me.
I have a text file that is in the same directory as the script file. When I call file open, it tells me it cannot see it.

filehandle = open('box.txt')

The code returns an error that the file or directory doesn't exist.
What should I do to open it.