Dunder Methods or “magic methods”

• predefined special methods, preceded and followed by two underscores.
• example __ init__ or __ str__

A list of Dunder Methods

• Object Initialization: __ init__
  • Object Representation: str, repr
  • Enable Iteration: len, getitem, reversed
  • Operator Overloading for Comparing Accounts: eq, lt
  • Operator Overloading for Merging Accounts: add
  • Method invocation / Callable Python Objects: call
  • Context Manager Support and the With Statement: enter, exit

Basic Statistics in Python — Probability

• probability is how likely it is for something to happen; the chance of event occurence
• normal distribution: 2D bell shaped, symmetrical graph in which the x-axis represents the values of events and the y-axis represents the probability associated with each event, from 0 to 1.

### Central Limit Theorem

### Z-score

The Z-score is a simple calculation that answers the question, “Given a data point, how many standard deviations is it away from the mean?” The equation below is the Z-score equation