我想提取以$sign开头的数字。例如：545美元

Question

import re
test = 'We four guys, live at 2nd street of Malibeu. I had a cash of $248 in my pocket. I got a ticket with serial number ABC1234.'

arr = []
arr = re.findall(r'[0-9]+', test)
print(arr)

我试过这样从字符串中获取数字。但它只返回字符串

我想在数字前面加上$号。 我需要打印序列号，比如 ABC1234

我得到的结果是：

[2, 248, 1234]

我需要像这样的输出：

用$符号：

$248

用ABC：

ABC1234

请帮我解决这个问题

Answer 1

在匹配数字之前，您可以选择匹配$或大写字符

(?:\$|\b[A-Z]+)?\d+

模式匹配

• (?:非捕获组
  • \$匹配$
  • |或
  • \b[A-Z]+单词边界，匹配1+大写字符
• )?关闭非捕获组并将其设置为可选
• \d+匹配1+个数字

Regex demoPython demo

范例

import re
test = 'We four guys, live at 2nd street of Malibeu. I had a cash of $248 in my pocket. I got a ticket with serial number ABC1234.'

arr = re.findall(r'(?:\$|\b[A-Z]+)?\d+', test)
print(arr)

输出

['2', '$248', 'ABC1234']

---

如果您不想只匹配数字，则非捕获组不应是可选的，您可以在末尾添加单词边界\b，以防止部分匹配：

 (?:\$|\b[A-Z]+)\d+\b

Regex demoPython demo

import re
test = 'We four guys, live at 2nd street of Malibeu. I had a cash of $248 in my pocket. I got a ticket with serial number ABC1234.'

arr = re.findall(r'(?:\$|\b[A-Z]+)\d+\b', test)
print(arr)

输出

['$248', 'ABC1234']