带有 python / re.match 的正则表达式不起作用

Question

I've got stringText like that

sText ="""<firstName name="hello morning" id="2342"/>
<mainDescription description="cooking food blog 5 years"/>
<special description="G10X, U16X, U17X, G26X, C32X, G34X, G37X, U39X, C40X, G46X,C49X, U54X, U55X, A58X"/> 
"""

I'd like receive:

cooking food blog 5 years

I tried many different regex

like:

p = re.compile('<mainDescription description=\"([^\"]+)\"\/>')
print re.match(p, sText)

or

p = re.compile(ur'<mainDescription description="([^"]+)"\/>')

and using (.+) according regex101.com my regex should work correctly, but it doesn't. I have no idea why

Answer 1

Try use findall():

print re.findall('<mainDescription description=\"([^\"]+)\"\/>', sText)

Output:

['cooking food blog 5 years']

Answer 2

Seems like it's because you're using re.match() instead of re.search() . re.match() Searches from the start of the string while re.search() searches anywhere. This works:

sText ="""<firstName name="hello morning" id="2342"/>
<mainDescription description="cooking food blog 5 years"/>
<special description="G10X, U16X, U17X, G26X, C32X, G34X, G37X, U39X, C40X, G46X,C49X, U54X, U55X, A58X"/> 
"""
p = re.compile('<mainDescription description=\"([^\"]+)\"\/>')
print re.search(p, sText).group(1)

By the way, you do not need to escape the quotation marks ( " ) if you're using ' meaning this is enough:

re.search('<mainDescription description="([^"]+)"/>', sText)

Answer 3

re.match returns a match object, from which you need to retrieve the desired group.

sText ="""<firstName name="hello morning" id="2342"/>
<mainDescription description="cooking food blog 5 years"/>
<special description="G10X, U16X, U17X, G26X, C32X, G34X, G37X, U39X, C40X, G46X,C49X, U54X, U55X, A58X"/> 
"""
r = re.compile("""<mainDescription description="(?P<description>[^"]+)"\/>""")
m = r.match(sText)
print m.group('description')

Note that it's also possible to access the group using the index (0 in this case) but I prefer to specify a keyword.