MEP

Mathematical Expression Parsing

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Stargazers over time

install

In the directory of MEP:

pip install .

or use setup.py to install:

python setup.py install

usage

formula

Use MEP.Formula and MEP.X to product a formula.

>>>import MEP
>>>f = MEP.Formula(2 * MEP.X - 1)

Formula objects are printable and __str__ method is defined, but text method is recommended.

>>>print(f)
<Formula f(x)=2*x-1>
>>>str(f)
'<Formula f(x)=2*x-1>'
>>>f.text()
'2*x-1'

curry

curry method can curry a formula and return the curried formula.

>>>f1 = MEP.Formula(X + Y)
>>>f2 = f1.curry(x=2)
>>>print(f2.text())
2+y

symbol

A Symbol object can be defined by users, a symbol's name must be a letter.

A = MEP.Symbol('a')
f = Formula(A * 2)

A formula can contain multiple symbols, and 'x', 'y', 'z' are built-in, they are default symbols in MEP.

Use variable symbols to get all defined symbols's sign, you can also visit sign to get the sign of a symbol.

>>>MEP.symbols
{'x', 'y', 'z', 'a'}

>>>A.sign
'a'

expression

Substitute a value to build a new expression.The substituted values should correspond to the symbols by using keyword arguments, the key names are symbols's signs.

>>>f = MEP.Formula(2 * MEP.X - 1)
>>>exp = f.subs(x=2) # an Expression object
>>>exp.value()
3

>>>print(exp)
<Expression f(x=2)=2*2-1>
>>>exp.text()
'2*2-1'

math

Class Math provides with some special functions, which can participate in formula generations.

>>>f = Formula(Math.abs(9 - MEP.X)) # equal to |9-x|
>>>exp = f.subs(x=12)
>>>exp.value()
3

Features in Development

• [ ] Show functions images with tkinter.
• [ ] Code for test (too lazy to write.
• [ ] Analyze formulas, such as calculating definition domains.
• [ ] Optimize the code.
• [ ] Consider removing "draw" or verifying whether it is still required. ...

Bugs/Requests

Please send bug reports and feature requests through github issue tracker.

About Author

Bilbili: 航sail654 Github: yuanhang2008 QQ: 远航

License

Copyright yuanhang2008, 2023.

Distributed under the terms of the MIT License.

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