expression.py

"""
This module shows how to create new integers by applying math expressions
on existing integers.
"""

import math


def main() -> None:
 # This is a simple integer
 x = 1

 # Its value can be used as part of expressions
 assert x + 1 == 2

 # An expression can be chained indefinitely. This concept of chaining
 # expressions is powerful because it allows us to compose simple pieces
 # of code into larger pieces of code over time
 assert x * 2 * 2 * 2 == 8

 # Division is tricky because Python 3.x returns 0.5 of type `float`
 # whereas Python 2.x returns 0 of type `int`. If this line fails, it
 # is a sign that the wrong version of Python was used
 assert math.isclose(x / 2, 0.5)

 # If an integer division is desired, then an extra slash must be
 # added to the expression. In Python 2.x and Python 3.x, the behavior
 # is exactly the same
 assert x // 2 == 0

 # Powers of an integer can be leveraged too. If more features are
 # needed, then leverage the builtin `math` library or a third-party
 # library. Otherwise, we have to build our own math library
 assert x * 2**3 == 8


if __name__ == "__main__":
 main()