ttable 0.6.2

Synopsis

tt is a library aiming to provide a Pythonic toolkit for working with Boolean expressions. Please check out the project site for more information.

Installation

tt is tested on CPython 2.7, 3.3, 3.4, 3.5, and 3.6. You can get the latest release from PyPI with:

pip install ttable

Features

tt lets you do a few things with your prized Boolean expressions. Let’s start by parsing one:

>>> from tt import BooleanExpression
>>> b = BooleanExpression('A impl not (B nand C)')
>>> b.tokens
['A', 'impl', 'not', '(', 'B', 'nand', 'C', ')']
>>> b.symbols
['A', 'B', 'C']
>>> print(b.tree)
impl
`----A
`----not
     `----nand
          `----B
          `----C

Then transform it a couple of times:

>>> from tt import apply_de_morgans, to_cnf, to_primitives
>>> b = to_primitives(b)
>>> b
<BooleanExpression "not A or not (not B or not C)">
>>> b = apply_de_morgans(b)
>>> b
<BooleanExpression "not A or (not not B and not not C)">
>>> b = to_cnf(b)
>>> b
<BooleanExpression "(not A or B) and (not A or C)">

Poke around its structure:

>>> b.is_cnf
True
>>> b.is_dnf
False
>>> for clause in b.iter_clauses():
...     print(clause)
...
not A or B
not A or C

Find all of its SAT solutions:

>>> for sat_solution in b.sat_all():
...     print(sat_solution)
...
A=0, B=1, C=1
A=0, B=1, C=0
A=0, B=0, C=1
A=0, B=0, C=0
A=1, B=1, C=1

Or just find one:

>>> with b.constrain(A=1):
...     b.sat_one()
...
<BooleanValues [A=1, B=1, C=1]>

Turn it into a truth table:

>>> from tt import TruthTable
>>> t = TruthTable(b)
>>> print(t)
+---+---+---+---+
| A | B | C |   |
+---+---+---+---+
| 0 | 0 | 0 | 1 |
+---+---+---+---+
| 0 | 0 | 1 | 1 |
+---+---+---+---+
| 0 | 1 | 0 | 1 |
+---+---+---+---+
| 0 | 1 | 1 | 1 |
+---+---+---+---+
| 1 | 0 | 0 | 0 |
+---+---+---+---+
| 1 | 0 | 1 | 0 |
+---+---+---+---+
| 1 | 1 | 0 | 0 |
+---+---+---+---+
| 1 | 1 | 1 | 1 |
+---+---+---+---+

And compare it to another truth table:

>>> other_table = TruthTable(from_values='111x00x1')
>>> other_table.ordering
['A', 'B', 'C']
>>> for inputs, result in other_table:
...     print(inputs, '=>', result)
...
A=0, B=0, C=0 => True
A=0, B=0, C=1 => True
A=0, B=1, C=0 => True
A=0, B=1, C=1 => x
A=1, B=0, C=0 => False
A=1, B=0, C=1 => False
A=1, B=1, C=0 => x
A=1, B=1, C=1 => True
>>> other_table.equivalent_to(t)
True

License

tt uses the MIT License.