why it showed that the argument of my function was not defined?

[Tony]

place it in quotes:

load_atlas('ala-acton.txt')

Thank you for your help.When i place in the quotes the program is going to open a file called "filename" which does not exist

here is the error message

Error:
line 6, in load_atlas
    with open('filename', 'r') as csv_file:
FileNotFoundError: [Errno 2] No such file or directory: 'filename'

may I ask do we have a method to modify it?

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#3

I got it!!!again,Thank you for you help,I was confused by this for a while.