davidgilbertson / printi Goto Github PK

🚧 This Python package is a WIP.

Still TODO:

☐ Publish to PyPi/conda-forge

☐ Make it work for older versions than 3.10

☐ Test with macOS/Linux

☐ Test with Jupyter

Printi watches what you print, and if it sees a number that can be displayed in a more insightful way, it will tell you.

For example, the last line in the code snippet below is printi telling you that -2.4674011002723395 is very very close to -π²/4:

>>> import cmath
>>> import printi
>>> printi.watch()
>>> cmath.log(1j) ** 2
(-2.4674011002723395+0j)
💡 -2.4674011002723395 ≈ -π²/4

The printi function is a drop-in replacement for print. It has the same API as the builtin print function.

To use printi as a function, you'll need to use from printi import printi (for all other methods it is enough to use import printi).

Rather than use printi() directly, you can tell it to watch stdout. You can add this to your startup script referenced by PYTHONSTARTUP.

Example Python startup file using Printi:

# This file is referenced in PYTHONSTARTUP
import sys
from pathlib import Path

sys.path.append(str(Path.home() / 'path/to/printi/src'))
from printi import printi

printi.watch()

Now when you start any interactive session, Printi will be watching.

Printi will stop watching.

Updates the configuration options for Printi. All possible keys, and their defaults are:

printi.update_config(
  min_denominator=3,
  max_denominator=100,
  tol=1e-9,
  symbol='💡',
  specials={
      math.pi: 'π',
      math.tau: 'τ',
      math.e: 'e',
  },
)

• min_denominator is the minimum denominator.

• max_denominator is the max. If this is set too high, you'll get false positives

• tol is the tolerance. This is passed to math.isclose as rel_tol

• symbol. Change this if you don't like the light bulb. Why don't you like the light bulb?

• specials is a dict of float/string pairs that will be added to the existing dict. To remove a key, pass None as the value. Example below:

  >>> printi.update_config(specials={1.2345678: 'λ'})
  >>> 'How do you like 1.2345678?'
  'How do you like 1.2345678?'
  💡 1.2345678 ≈ λ

Printi will only find 'representations' in the form a ± b * c ** d where

• a is an integer
• b is a fraction (respecting min/max denominator)
• c is either one of the 'special' values, or a digit
• d is a selection of positive and negative integers and fractions

Check out the tests in /tests/test_printi.py for lots of examples.

• Run pipenv run test to run the tests
• Run py -m build to build