README.md

python.math.expression.parser.pymep

pymep can parse or evaluate math expressions and it is tested using matlab/octave

This algorithm does not use a decision tree. It is a kind of Recursive Ascent Parser (https://en.wikipedia.org/wiki/Recursive_ascent_parser). In fact, it is LR parser (Left-Right Parser) without backtracking. This recursive algorithm is faster than decision trees

pypi version

https://pypi.org/project/pymep/

Installation

pip install pymep

Features

math functions

• sin, cos, tan, sinh, cosh, tanh, asin, acos, atan, log, log10, sqrt
• pi, e
• real or complex numbers

parentheses

fx= 2*(e*2)

variables

• Expressions in vars

  var = {"x":"1+2+3+4+5", "Z":1}
  eval(" 2*(-(((z*3)*sqrt(x^(2)))+3))",var)
  

Examples

Parse or eveluate expressions with real numbers:

from pymep.realParser import parse
from pymep.realParser import eval


#Real Expresion parser
fx="cos(10)"
print(parse(fx))

xi=5
fx = "1 + x"
print(eval(fx, xi))

var = {"x":"1+1", "Z":1}
eval(" 2*(-(((z*3)*sqrt(x^(2)))+3))",var)

Parse or evaluate expressions with complex numbers:

from pymep.complexParser import parse
from pymep.complexParser import eval
from pymep.complex import Complex

#Operation with complex numbers
a = Complex(1,2)
print(a.__radd__(10).__complex__())
print(Complex.radd(10, a).__complex__())


#Complex Expresion parser
fx="cos(10+2j)"
print(parse(fx).__complex__())

xi=5
fx = "1 +j+x"
print(eval(fx, xi).__complex__())

var={"x":"1+2j", "Y":complex(2,1)}
f_x = "x-y"
eval(f_x,var).__complex__()

There is a full list of examples inside!!

How to execute the tests

from pymep.realParserTest import functionXTest;

p = functionXTest();

p.test_one();
p.test_three();

Vulnerabilities

Zero vulnerabilities on https://snyk.io/vuln/pip:pymep

Notes

• The java version of this library is: https://github.com/sbesada/java.math.expression.parser
• Regarding to the OS where you excute the tests, it is possible that some tests fail beacause of rounding issues. The mathematical library that was used in this project is "math". In the future, it is possible that the math library changes.

Professional Services

If you are interested in logical parsers or any task related to parsers, you can consult my professional services page https://github.com/sbesada/professional.services

Donation

If you think that my work deserves a donation, you can do it: https://sbesada.github.io/