postfixcalc 0.8.1

the stupid postfix evaluator

postfixcalc

Simple, stupid but easy and powerful infix expression evaluator using postfix notation.

User Guide

How to use?

from postfixcalc import Calc

expr = "(-1) ^ 2 + 3 - 4 * 8 - 2 ^ 3"
calc = Calc(expr)

print(calc.answer)
print(type(calc.answer))

-36
<class 'int'>

Explanation

expression: (-1) ^ 2 + 3 - 4 * 8 - 2 ^ 3

which with the math operator precedence is:

expression: ((-1) ^ 2) + 3 - (4 * 8) - (2 ^ 3)
            = (1) + 3 - (32) - (8)
            = 4 - 32 - 8
            = -28 - 8
            = -36

Initialization

calc = Calc(
    '(2 ^ 32) ^ (2 ^ 15) + -1',
    calc_timeout=1,         # timeout for the calculation (in seconds)
    str_repr_timeout=1.5    # timeout to generate the string representation (in seconds)
)

print(f"'(2 ^ 32) ^ (2 ^ 15)'s answer has '{len(calc.stranswer)}' digits")

'(2 ^ 32) ^ (2 ^ 15)'s answer has '315653' digits

print(f'answer is: {calc.stranswer[:5]}...{calc.stranswer[-5:]}')

answer is: 67411...79135

Other Attributes

from rich.pretty import Pretty
from rich import print as rprint

rprint(calc.parsed)

<ast.BinOp object at 0x7f93380b1330>

rprint(calc.extracted)

[
    (
        [
            (
                [([2], <ast.Pow object at 0x7f933cc8d150>, [32])],
                <ast.Pow object at 0x7f933cc8d150>,
                [([2], <ast.Pow object at 0x7f933cc8d150>, [15])]
            )
        ],
        <ast.Add object at 0x7f933cc8cf10>,
        [(<ast.USub object at 0x7f933cc8d570>, [1])]
    )
]

rprint(calc.flattened)

(
    (
        (([2], <ast.Pow object at 0x7f933cc8d150>, [32]),),
        <ast.Pow object at 0x7f933cc8d150>,
        (([2], <ast.Pow object at 0x7f933cc8d150>, [15]),)
    ),
    <ast.Add object at 0x7f933cc8cf10>,
    (<ast.USub object at 0x7f933cc8d570>, [1])
)

rprint(calc.strparenthesized)

(((2 ^ 32)) ^ ((2 ^ 15))) + (-1)

rprint(calc.listparenthesized)

['(', '(', '(', 2, '^', 32, ')', ')', '^', '(', '(', 2, '^', 15, ')', ')', ')', '+', '(', '-1', ')']

rprint(calc.numerized)

['(', '(', '(', 2, '^', 32, ')', ')', '^', '(', '(', 2, '^', 15, ')', ')', ')', '+', '(', -1, ')']

rprint(calc.postfix)

[2, 32, '^', 2, 15, '^', '^', -1, '+']

rprint(f'{calc.stranswer[:5]}...{calc.stranswer[-5:]}')

67411...79135

Calc Documentation