Python 正则表达式在论文中获得引用

Question

我正在使用 this code 从文本中提取引文：

#!/usr/bin/env python3
# https://stackoverflow.com/a/16826935

import re
from sys import stdin

text = stdin.read()

author = "(?:[A-Z][A-Za-z'`-]+)"
etal = "(?:et al.?)"
additional = "(?:,? (?:(?:and |& )?" + author + "|" + etal + "))"
year_num = "(?:19|20)[0-9][0-9]"
page_num = "(?:, p.? [0-9]+)?"  # Always optional
year = "(?:, *"+year_num+page_num+"| *\("+year_num+page_num+"\))"
regex = "(" + author + additional+"*" + year + ")"

matches = re.findall(regex, text)
matches = list( dict.fromkeys(matches) )
matches.sort()

#print(matches)
print ("\n".join(matches))

但是，它会将一些大写单词识别为作者姓名。比如在文中：

Although James (2020) recognized blablabla, Smith et al. (2020) found mimimi. 
Those inconsistent results are a sign of lalala (Green, 2010; Grimm, 1990). 
Also James (2020) ...

输出将是

Also James (2020)
Although James (2020)
Green, 2010
Grimm, 1990
Smith et al. (2020)

有没有办法在不删除整个匹配项的情况下将上述代码中的某些单词“列入黑名单”？我希望它能够识别 James 的工作，但从引文中删除了“Also”和“Although”。

提前致谢。

Answer 1

你可以使用

author = r"(?:[A-Z][A-Za-z'`-]+)"
etal = r"(?:et al\.?)"
additional = f"(?:,? (?:(?:and |& )?{author}|{etal}))"
year_num = "(?:19|20)[0-9][0-9]"
page_num = "(?:, p\.? [0-9]+)?"  # Always optional
year = fr"(?:, *{year_num}{page_num}| *\({year_num}{page_num}\))"
regex = fr'\b(?!(?:Although|Also)\b){author}{additional}*{year}'
matches = re.findall(regex, text)

请参阅Python demo 和resulting regex demo。

主要区别在于regex = fr'\b(?!(?:Although|Also)\b){author}{additional}*{year}'，如果紧靠右边的单词是Although或Also，\b(?!(?:Although|Also)\b)部分将失败。

另外，请注意我转义了应该与文字点匹配的点，并使用 f 字符串使代码看起来更紧凑。

Answer 2

这是我的答案，之前的答案不适用于某些引用。

regexr.com/6er6n

我从其他来源获得的这个答案，但它不适用于另一种类型的引文文本。我的版本修复了这个问题：

citationsRegex = r"\b(?!(?:Although|Also)\b)(?:[A-Z][A-Za-z'`-]+)(?:,? (?:(?:and |& )?(?:[A-Z][A-Za-z'`-]+)|(?:et al.?)))*(?:,? *(?:19|20)[0-9][0-9](?:, p\.? [0-9]+)?| *\((?:19|20)[0-9][0-9](?:, p\.? [0-9]+)?\))"