擅长:python、mysql、java
<pre><code>import re
def mask(string, digits_to_keep=4, mask_char='x'):
num_of_digits = sum(map(str.isdigit, string))
digits_to_mask = num_of_digits - digits_to_keep
masked_string = re.sub('\d', mask_char, string, digits_to_mask)
return masked_string
</code></pre>
<p>这样可以得到:</p>
^{pr2}$