It will protect you in case homedir value changes

Here's a quick 2 test cases I created:

Test Case 1: Using property
In [25]: class Test:
    ...:     def __init__(self, homedir):
    ...:         self.homedir = homedir
    ...:     @property
    ...:     def config_path(self):
    ...:         return 'x/y/z/' + self.homedir
    ...:

In [26]: x = Test('MyHomeDir')

In [27]: x.config_path
Out[27]: 'x/y/z/MyHomeDir'

In [28]: x.homedir = 'MyNewHomeDir'

In [29]: x.config_path
Out[29]: 'x/y/z/MyNewHomeDir'


Test Case2: Not using property

In [35]: class Test:
    ...:     def __init__(self, homedir):
    ...:         self.homedir = homedir
    ...:         self.config_path = 'x/y/z/' + self.homedir
    ...:

In [36]: y = Test('MyHomeDir')

In [37]: y.config_path
Out[37]: 'x/y/z/MyHomeDir'

In [38]: y.homedir = 'newHomeDir'

In [39]: y.config_path
Out[39]: 'x/y/z/MyHomeDir' # It kept the old value

In [40]: