<p>下面是一种使用<a href="https://docs.python.org/2/library/re.html" rel="nofollow noreferrer">^{<cd1>}</a>的方法:</p>
<pre><code>import re
l = ['[ 1.1 ] 1. a electronic bill presentment system.','[ 1.2 ] a network.']
[re.sub(r'\[\s*\d+\.*\d*\s*\]\s+(?:\d+\.\s*)?', '', s) for s in l]
# ['a electronic bill presentment system.', 'a network.']
</code></pre>
<p>见<a href="https://regex101.com/r/JVPUbx/3" rel="nofollow noreferrer">demo</a></p>
<hr/>
<p>使用更大的字符串列表进行测试:</p>
<pre><code>l = ['[ 1.1 ] 1. a electronic bill presentment system.',\
'[ 1.2 ] a network.',\
'[ 1.3 ] a plurality of first stations, each associated with a respective one of a plurality of users and operable to transmit first requests for bills of its associated user via the network.',\
'[ 1.5 ] a plurality of second network stations, each associated with a respective one of a plurality of billers, configured to receive the transmitted second requests for bills and to transmit, responsive thereto, the requested bills of the associated user via the network.',\
'[ 1.6 ] wherein the bill availability information for the associated user identifies those of the plurality of billers having a bill available for that user without identifying an amount of the bill of each of the identified billers for the associated user.',\
'[ 2.1 ] 2. a method for presenting electronic bills.']
[re.sub(r'\[\s*\d+\.*\d*\s*\]\s+(?:\d+\.\s*)?', '', s) for s in l]
['a electronic bill presentment system.',
'a network.',
'a plurality of first stations, each associated with a respective one of a plurality of users and operable to transmit first requests for bills of its associated user via the network.',
'a plurality of second network stations, each associated with a respective one of a plurality of billers, configured to receive the transmitted second requests for bills and to transmit, responsive thereto, the requested bills of the associated user via the network.',
'wherein the bill availability information for the associated user identifies those of the plurality of billers having a bill available for that user without identifying an amount of the bill of each of the identified billers for the associated user.',
'a method for presenting electronic bills.']
</code></pre>