mutable_number.py

A class for representing mutable numbers in Python.

This makes a mutable version of a number (integer, complex, float) with all the special methods delegated to the underlying number.

This allows the number to have auxiliary information attached to it.

Example

Python 3.5.2 (default, Nov 17 2016, 17:05:23)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import mutable_number
>>> m = mutable_number.MutableNumber(3)
>>> m
3
>>> id(m)
140611097008224
>>> m+=1
>>> m
4
>>> id(m)
140611097008224
>>> class UnitNumber(mutable_number.MutableNumber):
...    def __init__(self, n, units):
...       super().__init__(n)
...       self.units = units
...    def __repr__(self):
...       return super().__repr__()+' '+self.units
...
>>> un = UnitNumber(4, 'Volts')
>>> un
4 Volts
>>> un + 8
12
>>> un += 1
>>> un
5 Volts
>>> un *= 1j
>>> un
5j Volts

Notes

Has this basic idea been done before? Please let me know what I've re-invented.