reading-notes

Class 04

Dunder Methods

• Special/Magic Methods - set of predefined methods to enrich classes. Use Dunders
• Emulate the behavior of built-in types

class NoLenSupport:
    pass

>>> obj = NoLenSupport()
>>> len(obj)
TypeError: "object of type 'NoLenSupport' has no len()"

class LenSupport:
    def __len__(self):
        return 42

>>> obj = LenSupport()
>>> len(obj)
42

Dunder Methods List

• ` init`
• __repr__
• __str__
• __len__ -
• __getitem__ -
• __reversed__ -
• __eq__
• __lt__
• __add__
• __call__
• __enter__
• __exit__

Probability

• Odds of something happening
  • What could occur
  • Flip a coin 10 times and count how many times you get heads/tails.
  • May have an abnormally high count of heads or tails
  • The more times you run the test the closer you get to the true odds
• Three Sigma Rule - expression of how many observations fall within a certain distance of mean
• Z-score - “Given a data point, how many standard deviations is it away from the mean”

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