Python regex search only finding the first pattern

Question

I am using python's re module to search in a string for certain words.

For a simple example, I have a list called valid_words and a string called valid_string.

valid_string = "Use Use%"
valid_words = ['Use', 'Use%']

for header in valid_words:
  regex_search = re.search("\\b"+header+"\\b",  valid_string)
  if regex_search:
    print header

However, this only returns Use and not Use%. I think this is because the % in 'Use%' is being treated as a regular expression. Am I correct? Is there a way to get around this?

mgilson · Accepted Answer · 2013-05-22 21:06:52Z

2

The problem here is that you're using word boundaries, however, with your second word 'Use%', the word boundary actually occurs between e and %. For example:

>>> re.search('.\\b','Use%').group(0)
'e'

answered May 22, 2013 at 21:06

mgilson

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3 Comments

eltaco431 Over a year ago

Oh, I see. So is there a way to move the boundary to the end of each word in valid_words?

mgilson Over a year ago

@Fsun -- It's hard to say what is best to do here. It seems like a simple str.split would be what you want, but it's hard to say ...

eltaco431 Over a year ago

Thank you. But, str.split actually isn't viable in my situation. For example, an element in valid_words may be "He llo", so the regex search will look for "He llo" in valid_string.

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