NumDict¶

class NumDict¶

A dictionary that you can do basic math with as though it was a number.

Supported Operations:

Example

>>> from collectionish import NumDict
>>>
>>> nd = NumDict(a =-3.56, b=6.4)
>>> nd
NumDict({'a': -3.56, 'b': 6.4})

numdicts support arithmetic via builtin operators on scalar with scalar values:

>>> nd + 1
NumDict({'a': -2.56, 'b': 7.4})

>>> 1 + nd
NumDict({'a': -2.56, 'b': 7.4})

including inplace ops:

>>> nd += 1
>>> nd
NumDict({'a': -2.56, 'b': 7.4})

likewise with other numdicts

>>> nd * NumDict(a=2, b=4)
NumDict({'a': -5.12, 'b': 29.6})

>>> nd *= NumDict(a=2, b=4)
>>> nd
NumDict({'a': -5.12, 'b': 29.6})

when doing math on numdicts that dont share all keys we try and stay do the sensible thing….

keys are taken from the lefthand numberdict and will be ordered as such. so any extra keys in the rightand numberdict will be ignored.

>>> x = NumDict(a =-3.56, b=6.4)
>>> y = NumDict(a =2, b=4, extra=6)
>>> x * y
NumDict({'a': -7.12, 'b': 25.6})

if a key is missing from the righthand numberdict we treat the missing bit as the identity value for that operation:

0 for addition, subtraction &: 1 for multiplication, division, exponentiation, floor division and modulus

>>> x = NumDict(a =-3.56, b=6.4)
>>> y = NumDict(a =2, extra=6) # no b!
>>> x * y
NumDict({'a': -7.12, 'b': 6.4})

numdicts support basic builtins like round and abs:

>>> nd = NumDict(a = -3.56, b=3.1, c=6.4, d=2)
>>> round(nd)
NumDict({'a': -4, 'b': 3, 'c': 6, 'd': 2})

>>> round(nd, 1)
NumDict({'a': -3.6, 'b': 3.1, 'c': 6.4, 'd': 2})

>>> abs(nd)
NumDict({'a': 3.56, 'b': 3.1, 'c': 6.4, 'd': 2})

as well as a couple extra aggregation methods:

>>> nd.sum()
7.94

>>> nd.min()
-3.56

>>> nd.max()
6.4

>>> nd.mean()
1.985