PermissionError: [Errno 13] in Python

When doing;

a_file = open('E:\Python Win7-64-AMD 3.3\Test', encoding='utf-8')

…you’re trying to open a directory as a file, which may (and on most non UNIX file systems will) fail.

Your other example though;

a_file = open('E:\Python Win7-64-AMD 3.3\Test\a.txt', encoding='utf-8')

should work well if you just have the permission on a.txt. You may want to use a raw (r-prefixed) string though, to make sure your path does not contain any escape characters like \n that will be translated to special characters.

a_file = open(r'E:\Python Win7-64-AMD 3.3\Test\a.txt', encoding='utf-8')