正则表达式在python中搜索if条件

Question

I am trying to search whole word pid in the link but somewhat this is also searching for id in this code

    for a in self.soup.find_all(href=True):

        if 'pid' in a['href']:
            href = a['href']
            if not href or len(href) <= 1:
                continue
            elif 'javascript:' in href.lower():
                continue
            else:
                href = href.strip()
            if href[0] == '/':
                href = (domain_link + href).strip()
            elif href[:4] == 'http':
                href = href.strip()
            elif href[0] != '/' and href[:4] != 'http':
                href = ( domain_link + '/' + href ).strip()
            if '#' in href:
                indx = href.index('#')
                href = href[:indx].strip()
            if href in links:
                continue

            links.append(self.re_encode(href))

Answer 1

If you mean that you want it to match a string like /pid/0002 but not /rapid.html , then you need to exclude word characters on either side. Something like:

>>> re.search(r'\Wpid\W', '/pid/0002')
<_sre.SRE_Match object; span=(0, 5), match='/pid/'>
>>> re.search(r'\Wpid\W', '/rapid/123')
None

If 'pid' might be at the start or end of the string, you'll need to add extra conditions: check for either the start/end of line or a non-word character:

>>> re.search(r'(^|\W)pid($|\W)', 'pid/123')
<_sre.SRE_Match object; span=(0, 4), match='pid/'>

See the docs for more information on the special characters.

You could use it like this:

pattern = re.compile(r'(^|\W)pid($|\W)')
if pattern.search(a['href']) is not None:
    ...