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