If there difference between `\A` vs `^` (caret) in regular expression?
<p>Python's <a href="https://docs.python.org/2/library/re.html" rel="nofollow"><code>re</code> module documentation</a> says:</p>

<blockquote>
  <p><code>^</code>: (Caret.) Matches the start of the string, and in MULTILINE mode also matches immediately after each newline.</p>
  
  <p><code>\A</code>: Matches only at the start of the string.</p>
</blockquote>

<p>Is there any difference when using them?</p>

<p><code>\A</code> is unambiguous string start anchor. <code>^</code> can change its behavior depending on whether the <code>re.M</code> modifier is used or not.</p>

<p><em>When to use <code>\A</code> and when to use <code>^</code>?</em></p>

<p>When you want to match either start of a string <em>OR</em> a line, you use <code>^</code>, when you only need to match the start of a string <em>regardless of any modifiers</em>, use <code>\A</code>. You may re-use one and the same string pattern but compile it with different flags.</p>

<p>This also means that if you are using <code>re.M</code> flag, and you want to match the string start and then line start positions, you will mix the <code>\A</code> and <code>^</code> inside that pattern.</p>

python regex python-2.7