（Python）有没有办法从整个字符串中提取子字符串/数字？

Question

我有一个包含唯一实用程序数据的元组列表，包括消耗量（立方英尺）、加仑水和估计价格。有 13 个元组，一个用于一年中的每个月，一个用于年末的总消费。我的目标是提取这三个信息，将它们存储到数据框中，并最终将它们导出到 Excel 工作表中。

这是我将元组排序为字符串后的样子。 （我将它们迭代并排序为字符串的原因是因为它们最初是 Soup(BeautifulSoup) 格式，很难组织成列表。）

这是一个元组的样子：

[\'<area alt="" coords="151,115,181,382" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 49,094.00 CF (367,223.12 Gallons)  &lt;br /&gt; Approximate Charge = $5,073.42\\\');" shape="rect"/>\']'

下面是元组的完整列表。唯一的例外是最后（第 13 个）元组列出了“总消费”而不是“消费”

['[\'<area alt="" coords="113,88,143,382" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'**Consumption = 54,070.00 CF (404,443.60 Gallons)**  &lt;br /&gt; **Approximate Charge = $5,587.65**\\\');" shape="rect"/>\']', '[\'<area alt="" coords="151,115,181,382" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 49,094.00 CF (367,223.12 Gallons)  &lt;br /&gt; Approximate Charge = $5,073.42\\\');" shape="rect"/>\']', '[\'<area alt="" coords="188,99,218,382" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 51,921.00 CF (388,369.08 Gallons)  &lt;br /&gt; Approximate Charge = $5,365.57\\\');" shape="rect"/>\']', '[\'<area alt="" coords="226,125,256,382" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 47,122.00 CF (352,472.56 Gallons)  &lt;br /&gt; Approximate Charge = $4,869.63\\\');" shape="rect"/>\']', '[\'<area alt="" coords="263,101,294,382" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 51,687.00 CF (386,618.76 Gallons)  &lt;br /&gt; Approximate Charge = $5,341.39\\\');" shape="rect"/>\']', '[\'<area alt="" coords="301,139,331,382" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 44,643.00 CF (333,929.64 Gallons)  &lt;br /&gt; Approximate Charge = $4,613.45\\\');" shape="rect"/>\']', '[\'<area alt="" coords="339,176,369,382" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 37,770.00 CF (282,519.60 Gallons)  &lt;br /&gt; Approximate Charge = $4,010.80\\\');" shape="rect"/>\']', '[\'<area alt="" coords="376,382,407,383" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 0.00 CF (0.00 Gallons)  &lt;br /&gt; Approximate Charge = $0.00\\\');" shape="rect"/>\']', '[\'<area alt="" coords="414,382,444,383" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 0.00 CF (0.00 Gallons)  &lt;br /&gt; Approximate Charge = $0.00\\\');" shape="rect"/>\']', '[\'<area alt="" coords="452,382,482,383" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 0.00 CF (0.00 Gallons)  &lt;br /&gt; Approximate Charge = $0.00\\\');" shape="rect"/>\']', '[\'<area alt="" coords="489,382,519,383" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 0.00 CF (0.00 Gallons)  &lt;br /&gt; Approximate Charge = $0.00\\\');" shape="rect"/>\']', '[\'<area alt="" coords="527,382,557,383" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Consumption = 0.00 CF (0.00 Gallons)  &lt;br /&gt; Approximate Charge = $0.00\\\');" shape="rect"/>\']', '[\'<area alt="" coords="653,68,733,382" onmouseout="DisplayTooltip(\\\'\\\');" onmouseover="DisplayTooltip(\\\'Total Consumption = 336,307 CF (2,515,576 Gallons) &lt;br /&gt; Approximate Charge = $34,861.91\\\');" shape="rect"/>\']']

我写了这个正则表达式来提取加仑：

gallons = re.search('CF((.*)Gallons)', test_line)
print(gallons)

哪个输出这个：

<re.Match object; span=(128, 150), match='CF (404,443.60 Gallons'>

这并没有真正让它变得更容易，因为现在我必须找到一种方法来提取 '404,443,.60'

如果有人可以推荐一种从元组列表中提取这三段数据的方法（假设我很可能必须在元组列表上创建某种形式的迭代）并将它们存储到一个数据帧中非常有帮助。最终目标是将这些数字存储到数据框中，并最终导出到 Excel 工作表中。

Answer 1

这可能会做你想做的事：

gallons = re.search(r'(?<=CF\s\()[\d,\.]*(?= Gallons)', test_line)

Answer 2

您可以使用捕获组，并通过匹配括号来使模式更加具体，并捕获组 1 中左括号后带有可选小数部分的数字。

\bCF\s\((\d+(?:\.\d+)*(?:,\d+(?:\.\d+)*)*)\sGallons\)

• \bCF\s 防止空匹配的单词边界，匹配 CF 和空格字符
• \(匹配(
• ( 捕获第 1 组
  • \d+(?:\.\d+)* 匹配 1+ 位数字和可选的小数部分
  • (?:,\d+(?:\.\d+)*)* 可选择重复匹配 , 和 1+ 位，可选小数部分
• )关闭第一组
• \sGallons\) 匹配一个空格字符和Gallons)

Regex demo | Python demo

例如

import re
 
pattern=r"\bCF\s\((\d+(?:\.\d+)*(?:,\d+(?:\.\d+)*)*)\sGallons\)"
 
strings = [r'Consumption = 49,094.00 CF (367,223.12 Gallons)']
 
for s in strings:
    m = re.search(pattern, s)
    if m:
      gallons = m.group(1)
      print(gallons)

输出

367,223.12

Answer 3

你可以得到匹配的组：

import re
re_gallons = re.compile(r'CF \((.*)Gallons\)')
print(re_gallons.search(test_line).group(1))