如何從字符串中刪除兩個標簽之間所有出現的子字符串？

Question

我正在嘗試刪除以下字符串中<pre><code>和</code></pre>之間的所有子字符串，並且還刪除<pre><code>和</code></pre> ：

txt = '<p>Large pythons were <pre><code> the subject of many </code></pre> a news story </p>\n last year due to the fact that there were at least two deaths <pre><code> directly attributable to them </code></pre>. Tragically, the deaths would not have happened had <pre><code> the owners of these snakes kept them </code></pre> safely, and responsibly, contained. The following article, by David Chiszar, Hobart M. Smith, <a href= Albert Petkus and Joseph Dougherty </a>, was recently published in the Bulletin of the Chicago Herpetological Society, and represents the first clear, and accurate, <p> account of the death that occurred July 1993</p>\n'

我編寫了以下代碼，以刪除三個子字符串出現時的這些標記。

def remsubstr( s, first, last ):
if first and last not in s:
    return s

try:
    start = s.index( first ) + len( first )
    end = s.index( last, start )
    d = (s[:start] +" "+ s[end:]).replace('<p>', '').replace('</p>\n', '')
    started = d.index("<pre><code>" )
    ended = d.index("</code></pre>") + len("</code></pre>")
    nw = d.replace(d[started:ended], '')

    if first and last in nw:
        start = nw.index( first ) + len( first )
        end = nw.index( last, start )
        d1 = (nw[:start] +" "+ nw[end:])
        started = d1.index("<pre><code>" )
        ended = d1.index("</code></pre>") + len("</code></pre>")
        nw1 = d1.replace(d1[started:ended], '')

        if first and last in nw1:
            start = nw1.index( first ) + len( first )
            end = nw1.index( last, start )
            d2 = (nw1[:start] +" "+ nw1[end:])
            started = d2.index("<pre><code>" )
            ended = d2.index("</code></pre>") + len("</code></pre>")
            nw2 = d2.replace(d2[started:ended], '')
            return nw2

        return nw1

    return nw

except ValueError:
    return ""

我可以使用上面的示例代碼刪除所有必需的標簽：

remsubstr(txt,"<pre><code>", "</code></pre>")

結果：

'Large pythons were  a news story  last year due to the fact that there were at least two deaths . Tragically, the deaths would not have happened had  safely, and responsibly, contained. The following article, by David Chiszar, Hobart M. Smith, <a href= Albert Petkus and Joseph Dougherty </a>, was recently published in the Bulletin of the Chicago Herpetological Society, and represents the first clear, and accurate,  account of the death that occurred July 1993'

我有成千上萬的字符串，應針對該字符串應用函數以消除這種情況的多次出現。

尋找幫助來編寫代碼，該代碼將刪除標記之間的所有子字符串，並且適用於三個以上的子字符串/標簽實例。

Answer 1

我建議使用BeautifulSoup 。 在那里，您可以組合.find_all（）和.decompose（）。 在您的情況下，應該這樣做：

import bs4

txt = '<p>Large pythons were <pre><code> the subject of many </code></pre> a news story </p>\n last year due to the fact that there were at least two deaths <pre><code> directly attributable to them </code></pre>. Tragically, the deaths would not have happened had <pre><code> the owners of these snakes kept them </code></pre> safely, and responsibly, contained. The following article, by David Chiszar, Hobart M. Smith, <a href= Albert Petkus and Joseph Dougherty </a>, was recently published in the Bulletin of the Chicago Herpetological Society, and represents the first clear, and accurate, <p> account of the death that occurred July 1993</p>\n'
soup = bs4.BeautifulSoup(txt, "html.parser")
for tag in soup.find_all('pre'):
    if tag.find('code'):
        tag.decompose()

result = str(soup)

Answer 2

使用Beautiful Soup 4時 ，標准字符串操作對於XML文件中的嵌套不是最佳的。