正则表达式匹配两个特定字符并获取第一个数字，然后是那些字符

Question

如果用户输入VX 是 20 m/s VY 是 40 m/s VZ 是 60 m/s 。

预期结果是来自输入的 Axis VX 和 20。

下面的代码也可以识别其他数字 40 和 60。

(VX)|(vx)|(Vx)|(vX)|[0-9]

Answer 1

利用

(?P<axis>vx)\s+\w+\s+(?P<value>\d+)

添加re.IGNORECASE 。 请参阅正则表达式证明。

解释

 - Named Capture Group axis (?P<axis>vx)
   - vx matches the characters vx literally (case insensitive)
 - \s+ matches any whitespace characters between one and unlimited times, as many times as possible, giving back as needed (greedy)
 - \w+ matches any word characters between one and unlimited times, as many times as possible, giving back as needed (greedy)
 - \s+ matches any whitespace characters between one and unlimited times, as many times as possible, giving back as needed (greedy)
 - Named Capture Group value (?P<value>\d+)
   - \d+ matches a digits between one and unlimited times, as many times as possible, giving back as needed (greedy)

Python 代码演示：

import re
text = r'VX is 20 m/s VY is 40 m/s  VZ is 60 m/s'
p = re.compile(r'(?P<axis>vx)\s+\w+\s+(?P<value>\d+)', re.IGNORECASE)
match = p.search(text)
if match:
    print(match.groupdict())

结果： {'axis': 'VX', 'value': '20'}