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+--- Thread: Composition question (/thread-23587.html)
Composition question - kerzol81 - Jan-07-2020
Hi, I'm testing composition, and I don't understand the output in the log file.
Here is the script:
import os
import time
import logging
import datetime
class Logger:
logging.basicConfig(filename=datetime.datetime.today().strftime("%Y_%m_%d.log"),
format='%(asctime)s %(message)s',
datefmt='%Y-%m-%d %H:%M:%S',
level=logging.INFO)
@staticmethod
def log2file(message):
logging.info(message)
class Folder:
_path = ''
_files = []
def __init__(self, path):
if not os.path.exists(path):
message = "folder does not exist"
raise TypeError(message)
self.path = path
class Source:
def __init__(self, path):
self.path = Folder(path)
Logger.log2file("{} as source folder added".format(self.path))
class Destination:
def __init__(self, path):
self.path = Folder(path)
Logger.log2file("{} as source folder added".format(self.path))
class XLSBackup:
pass
s = Source('/home/kz/a')The output in the log file is like this:2020-01-07 10:55:56 <__main__.Folder object at 0x7f4af2ff9390> as source folder added
But I expected this:
2020-01-07 10:55:56 /home/kz/a as source folder added
RE: Composition question - buran - Jan-07-2020
Source.path is instance of Folder class.Folder class has no __repr__ or __str__ methods defined.Read https://docs.python.org/3/reference/datamodel.html#object.__repr__
https://docs.python.org/3/reference/datamodel.html#object.__str__
define
Folder.__str__ method or as alternative use Logger.log2file("{} as source folder added".format(self.path.path))
RE: Composition question - buran - Jan-07-2020
Just to note that defining THAT much classes is not necessary, e.g. Source and Destination classes are virtually the same and almost the same as Folder
RE: Composition question - kerzol81 - Jan-07-2020
Hi, thanks, I implemented __str__, and now it works lik a charm.
class Folder:
_path = ''
_files = []
def __init__(self, path):
if not os.path.exists(path):
message = "folder does not exist"
raise TypeError(message)
self.path = path
def __str__(self):
return self.path(Jan-07-2020, 11:06 AM)buran Wrote: Just to note that defining THAT much classes is not necessary, e.g. Source and Destination classes are virtually the same and almost the same as Folder
I know that, but it's just a composition testing. In the end there wont be 3 classes.
