Python 在特定单词后捕获特定数字

Question

I am trying to capture "book id:" (similar to isbn except this has numbers) numbers from this sentence. I looked at the ISBN number example on stack and tried different kind of combination of regex how ever I am not able to capture them into a single list. What am I missing here?

sentence="List of book ids that are important to read book id: A83827-121-1-23-1341-2315ad3  book id: N32-12-1-23-1341-2342  and  book id: A334121A313412342"
isbn = re.compile("(?:[0-9]{3}-)?[0-9]{1,5}-[0-9]{1,7}-[0-9]{1,6}-[0-9][A-Z]",re.IGNORECASE)

matches = []
for line in sentence:
    matches.extend(isbn.findall(line))
    print(line)

Trying to capture final output like this:

['A83827-121-1-23-1341-2315ad3','N32-12-1-23-1341-2342','A334121A313412342']

Answer 1

Be aware that your for loop will iterate over each character: you don't need it.

Here is the regex you could use:

isbn = re.compile(r"book id: ([\w-]+)")
print(isbn.findall(sentence))

Output:

['A83827-121-1-23-1341-2315ad3', 'N32-12-1-23-1341-2342', 'A334121A313412342']

Explanation:

• [\\w-]+ matches any (non-empty) sequence of alphanumerical characters ( \\w ) and hyphens.
• The parentheses denote a capture group, and findall will only return what is matched in that group, so it does not include "book id: ".