Port Python v2 function to v3

This v2 function gives a 开发者_如何学编程"NameError: global name 'file' is not defined" error when run in v3.

def from_file(filename, sep='\n'):  
    "Parse a file into a list of strings, separated by sep."  
    return file(filename).read().strip().split(sep)  

Could someone please provide a v3 version?

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Change the file call to open.