Reduce precision of constants in a string

reduce_precision.py

import re

def reduce_precision_of_constants_in_string(s, precision=3):
    # Find all constants in the string:
    constants = re.findall(r"\b[-+]?\d*\.\d+|\b[-+]?\d+\.?\d*", s)
    for c in constants:
        reduced_c = "{:.{precision}g}".format(float(c), precision=precision)
        s = s.replace(c, reduced_c)
 
    return s


s = "1.093840293 * exp(x1 * 0.00031823)"
print(reduce_precision_of_constants_in_string(s))

# >> '1.09 * exp(x1 * 0.000318)'"