sympy：如何表达逻辑“不”

Question

The following code would work to sympify logical expressions:

sympify('a&b') # And(a, b)
sympify('a|b') # Or(a, b)

But how do I get a result of Not(a) ?

Answer 1

It turns out the symbol you are looking for is ~ . See the following:

>>> from sympy import sympify
>>> sympify('a&b')
And(a, b)
>>> sympify('a|b')
Or(a, b)
>>> sympify('~a')
Not(a)