python贪婪匹配以及多行匹配的实例讲解

> re.findall(r"a(\d+", "a23b")
  ['2']
> re.findall(r"a(\d+)", "a23b")
  ['23']

> re.findall(r"a(\d+)b", "a23b")
  ['23']
> re.findall(r"a(\d+", "a23b")
  ['23']

> re.findall(r"a(\d+)b.+a(\d+)b", "a23b\na34b")
  []
> re.findall(r"a(\d+)b.+a(\d+)b", "a23b\na34b", re.S)
  [('23', '34')]
>

> re.findall(r"^a(\d+)b", "a23b\na34b")
  ['23']
> re.findall(r"^a(\d+)b", "a23b\na34b", re.M)
  ['23', '34']

> re.findall(r"a(\d+)b", "a23b\na23b")
  ['23', '23']