Python Regex To Find Arithmetic Expressions In Text Strings

I try to find arithmetic expressions in text strings. Possible arithmetic expression: 1/3 + 1/4 cos(30) + 25*3,75 sqrt(5) + sin(45) 5 != 6 2**4 + 100.000 = (2^3)^4 sqrt((0,25*8)/2)

Solution 1:

An example using recursive regex

([\d,.e]+|(cos|sin|sqrt)\((?R)\)|\([ ]*(?R)[ ]*\))([ ]*[-+*\/!=^]+[ ]*(?R))*

Could be improved to be more strict to match operators or numbers

• (?R) refering recursively the whole regex