Python Regex在开始时就可以匹配，但在结尾时不起作用

Question

I am fairly new at python, but have used regex for a while. What am I missing here:

>>> import re
>>> raceResuls = "2014 Results at:"
>>> raceDate = "Saturday, December 5, 2015"
>>> pattern = re.compile("(\d{4})")
>>> pattern.match(raceResuls).group(1)
'2014'
>>> pattern.match(raceDate).group(1)

Traceback (most recent call last):
  File "<pyshell#5>", line 1, in <module>
    pattern.match(raceDate).group(1)
AttributeError: 'NoneType' object has no attribute 'group'

Why does this match at the beginning of the string, but not at the end? I am using python 2.7 on windows and linux.

Answer 1

You should use search instead of match . According to the docs:

Python offers two different primitive operations based on regular expressions: re.match() checks for a match only at the beginning of the string , while re.search() checks for a match anywhere in the string (this is what Perl does by default).

So when you use match it's the same as using ^ in your regex (matches the position before the first character in the string).