Custom file class

[nilamo]

You don't need a base class to create a context manager, you just need to implement the enter/exit interface.

>>> class TimeHistory:
...   def __init__(self, filename):
...     self.filename = filename
...     self.fobj = None
...   def __enter__(self):
...     self.fobj = open(self.filename, "r")
...     return self
...   def __exit__(self, *args):
...     if self.fobj:
...         self.fobj.close()
...     self.fobj = None
...
>>> with TimeHistory('test.txt') as file:
...   print(file)
...
<__main__.TimeHistory object at 0x000001AA1BB40AF0>