/mo-math

Functions that are graceful in the face of null values

Primary LanguagePythonMozilla Public License 2.0MPL-2.0

More Math!

Basic math functions that have been stabilized to act well over Null/None/NaN

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Overview

Many of the basic math functions you know and love, with the additional benefit that they do not throw exceptions and do not return NaN.

These functions are all module methods. Be sure you call the functions with mo_math. prefix, like

import mo_math
mo_math.abs(-42)

or rename the functions

from mo_math import abs as mo_abs
mo_abs(-42)

This prevents confusion with the __builtin__ functions by the same name

Functions

Functions are generally conservative in the face of nulls: Specifically, they return Null if any of their operands are not a number.

Most functions need no introduction, but some are interesting:

  • round(value, decimal=7, digits=None) - Rounds to 7 decimal points, unless specified differently. Rounding to decimal=0 will return an int. The useful parameter here is digits, which rounds to a specified number of significant digits.
  • floor(value, mod=1) - The modulo parameter is used to specify the granularity of the floor function.
  • ceiling(value, mod=1) - Return the smallest value, that's equal or larger than value, with suitable granularity.
  • mod(value, mod=1) - Works on floats
  • approx_str(value) - Round values, and return text (unicode in py2, str in py3)
  • sign(v) - Missing from the Python library

The all-caps aggregate functions accept only one parameter; an iterable. They are decisive operators: Non-numbers are ignored, if no values are numbers then the aggregate will return Null.

  • COUNT(values)
  • SUM(values)
  • PRODUCT(values)
  • MIN(values)
  • MAX(values)

Crypto

The AES and RSA crypto functions provide structured input/output on top of cryptography library. The intent is to reveal the signed/encrypted structures so third parties can decode the data.