Classes Contain Methods
Sometimes we just want a collection of associated methods – think math.pi. In Python we could accomplish this by having a class that has no class or instance attributes and only static methods. Raymond Hettinger, a Python Language developer goes so far as to say the purpose of @staticmethod
is to attach methods to classes^{1}
So in Python a “bucket” of
class my_math:
@staticmethod
def pi():
return 3.1416
@staticmethod
def circle_area(radius):
return radius * radius * my_math.pi()
Here we have a static method that returns a value for π. This is my personal method for establishing a constant^{2}. This avoids the situation where pi can be overwritten.
.WIN2>python
Python 3.9.10 (tags/v3.9.10:f2f3f53, Jan 17 2022, 15:14:21) [MSC v.1929 64 bit (AMD64)] on win32
>>> import math
>>> print(math.pi)
3.141592653589793
>>> print(math.sin(math.pi))
1.2246467991473532e16 # essentially the correct answer (0.0)
>>> math.pi =2.0
>>> print(math.sin(math.pi))
0.9092974268256817 # very much not zero
>>>

Python Class Development Toolkit at https://www.youtube.com/watch?v=HTLu2DFOdTg&ab_channel=NextDayVideo. ↩︎

Python has been described as a language for consenting adults–there is no privacy and there are no constants. Every value and method can be accessed changed by a determined programmer ↩︎