如何在 python 中的字符串中搜索两个连续字符

Question

I have a string

x = Apple>Mango>+Orange

What I want is to output an error whenever the program sees in two consecutive character in which case the greater than (>) and the plus (+)

I tried using the re.search method, but it seems like I cant put in two characters

import re

x = "Apple>Mango>+Orange"

if re.search('>+', x):
    print("error")
else:
    print("no error")

When I run the program it always outputs error even though my output is Apple>Mango>Orange which should output no error since there's no consecutive characters in it. It seems like its treating only the character greater than (>) as it is.

Is there a better way to do this, need help.

Answer 1

As @ggorlen commented, when using regex patterns, some characters have special meaning. + stands for as many matches as possible, it is a match-one-or-more quantifir, and if you wish to use it as a literal string, then you must escape it by preceding a backlash \ :

Therefore, the pattern to use would be:

import re

x = "Apple>Mango>+Orange"

if re.search(r'>\+', x): #This pattern matches the literal strings ">+"
    print("error")
else:
    print("no error")