正则表达式计算 origin = "1 - 2 * ( ( 60 - 30 + ( -40.0 / 5 ) * ( 9 - 2 * 5 / 3 + 7 / 3 * 99 / 4 * 2998 + 10 * 568 / 14 )) - ( - 4 * 3 ) / ( 16 - 3 * 2))"

 #!/usr/bin/env python

 import re

 def f1(arg):

     return 1

 origin = "1 - 2 * ( ( 60 - 30 + ( -40.0 / 5 ) * ( 9 - 2 * 5 / 3 + 7 / 3 * 99 / 4 * 2998 + 10 * 568 / 14 )) - ( - 4 * 3 ) / ( 16 - 3 * 2))"

 print(eval(origin))

 while True:

     print(origin)

     ret = re.split("\(([^()]+)\)", origin,1)

     if len(ret) == 3:

         before = ret[0]

         content = ret[1]

         after = ret[2]

         r = f1(content)

         new_str = before + str(r) + after

         origin = new_str

     else:

         final = f1(origin)

         print(final)

         break