python 中的匹配模式在到达某个字符之前

Question

I have a scenario where I have two strings to check for a match but the matching should be happening until a specific character (in my case - ) is found. here is what I am doing with a positive look forward approach but it doesn't seem to work

txt1 = "ap1-tempora1yu"
txt2 = "ap1-gt4"
if re.search(".+?(?=-)", txt1) == re.search(".+?(?=-)", txt2):
    print("found")
else:
    print("not found")

I have also tried this regex patterns but no luck /^(.*?)-/ and /.+?(?=-)/ any help woud be great

Answer 1

As @oh_my_lawdy commented, you don't really need regex here. However, if you want to use it then the issue with your code is that re.search() returns a match object . For such objects even the value of the expression

re.search(".+?(?=-)", txt1) == re.search(".+?(?=-)", txt1)

(with the same string txt1 on both sides) is False . What you should compare instead are the actual substrings matching the pattern. These can be obtained using

re.search(".+?(?=-)", txt1).group(0)

More precisely this returns the first match group, but this is the only group in this case. In effect your code should be modified as follows:

txt1 = "ap1-tempora1yu"
txt2 = "ap1-gt4"
if re.search(".+?(?=-)", txt1).group(0) == re.search(".+?(?=-)", txt2).group(0):
    print("found")
else:
    print("not found")