擅长:python、mysql、java
<p>下面是一个提取相关子字符串的函数:</p>
<pre><code>def flank(seq, pp):
# 1: find the position of the AA preceding the '*' marker in the
# phosphopeptide
marked_pos = pp.find('*') - 1
if (marked_pos < 0):
raise ValueError("invalid phosphopeptide string")
# 2: find the phosphopeptide (without '*') in the sequence
pp_pos = s.find(pp.replace('*', ''))
if pp_pos == -1:
raise ValueError("phosphopeptide not found in the sequence")
# avoid a negative starting index
start = max(0, pp_pos + marked_pos - 6)
# 3: use slicing to produce the result
return seq[start : pp_pos + marked_pos + 7]
</code></pre>
<p>示例:</p>
^{pr2}$
<p>印刷品:</p>
<pre><code>IKKVSPTFDTNMV
</code></pre>