<pre><code>(?<=\S)(?<!\bAbstract)\n(?=\S)
</code></pre>
<p>你可以试试这个。看演示</p>
<p><a href="https://regex101.com/r/crj3aD/1" rel="nofollow noreferrer">https://regex101.com/r/crj3aD/1</a></p>
<p>Python脚本:</p>
<pre><code>inp = "Balanced Quantum Classical Evolutionary Algorithm(BQCEA)\n\nMuhammad Shahid, Hasan Mujtaba, Muhammad Asim, Omer Beg\n\nAbstract\nWith advancement in Quantum computing, classical algorithms are adapted and integrated\nwith Quantum properties such as qubit representation and entanglement', ' Although these\nproperties perform better however pre-mature convergence is the main issue in Quantum\nEvolutionary Algorithms(QEA) because QEA uses only the best individual to update quan-\ntum population', ' In this paper, we introduced a new way to update the quantum population\nof QEA to avoid premature convergence"
output = re.sub(r'(?<=\S)(?<!\bAbstract)\n(?=\S)', ' ', inp)
print(output)
</code></pre>
<p>还有更多的条件</p>
<pre><code>(?<=\S)(?<!\bAbstract)(?:\n|\\n)(?=\S)
</code></pre>
<p>在你的另一种情况下试试这个</p>
<p><a href="https://regex101.com/r/crj3aD/2" rel="nofollow noreferrer">https://regex101.com/r/crj3aD/2</a></p>