所以,我正在用python制作计算器(我是相对较新的),经过一番阅读后,我发现了关于re.sub的东西。我遇到的问题是,每当我运行该程序时,它都会在第9行中运行一个Trackback错误。如果有人知道该怎么做,那么任何建议将不胜感激。
import re
#The input should be an equation, for example 26 +(32-1).
a = input("Enter Equation:")
c = "("
#It is supposed to look for parenthesis and make a sub-string out of whats in it
if '(' and ')' in a:
a = re.sub(r'^[^(]+(','',a)
print(a)
追踪(最近通话):
File "main.py", line 8, in <module> a = re.sub(r'^[^(]+(','',a) missing ), unterminated subpattern at position 6
在正则表达式中,您必须转义括号,因为它们具有特殊含义:
a = re.sub(r'^[^(]+\(','',a)