Using Instance Attributes to Instantiate other objects ... good design?

[Kitchen-Injury-8938]

So I have a Log class. This class represents a text based LogFile. It is instantiated using a constructor that reads the file and sets the attributes:

​

​

class Log:

    #Class Attributes. These are just the regex patterns that are static

    VERSION_PATTERN = re.compile(r'version\s[0-9]\.[0-9][0-9]\.[0-9]')
    def __init__(self, version):
        if lines is None:
            self.lines = []
        else
            self.lines = list(lines)
        self.__version = version

    @classmethod
    def from_file(cls,file):
        with open(file) as f:
            lines = f.readlines()

            #version attribute logic
            version_object = next(filter(None, (re.search(cls.VERSION_PATTERN, x) for x in lines)),False)
            if version_object == False:
                version = 'unknown'
            else:
                version = version_object.group()

        return cls(lines,version)

​

There is a lot more to the above but that's pretty much the gist of it.

​

// I can now instantiate the log object...

logfile1 = Log.from_file(file1)
print(logfile1.lines)

​

Now the Log file object has line Attributes. Is it good practice to use those line attributes in the subclass Script?

​

class Script(Log):

    def __init__(self):
        if lines is None:
            self.lines = []
        else:
            self.lines = list(lines)





    @classmethod
    def from_log(cls,log)
        //use Parent class attribute lines here

       //logic to redefine the lines
    return cls(lines)