图案更换

时间:2015-02-15 22:17:18

标签: python regex pattern-matching

我是RegEx新手,仍然接受模式匹配。但我想了解模式替换。我希望更改句子中的货币模式,其中值可以是任何值且不可预测的,但总是采用以下格式:

<currency_symbol><number><number><dot><number><number><letter>

例如:

'mr x is worth $44.4m and mr y is worth $59.1m'

为:

'mr x is worth $44400000 and mr y is worth $59100000'

我设法匹配模式,但没有替换:

>>> import re
>>> sent = "mr x is worth $44.4m and mr y is worth $59.1m"
>>> print(re.findall(r'\$\d+\.\d+\m', sent))
['$44.4m', '$59.1m']

如何实现正则表达式模式替换?还是有比正则表达更好的方法?

1 个答案:

答案 0 :(得分:3)

像这样进行替换的最简单方法是使用re.sub repl函数:

>>> import re
>>> source = 'mr x is worth $44.4m and mr y is worth $59.1m'
>>> def sub_func(match):
    """Convert the match to the new format."""
    string = match.group(0)
    millions = int(float(string[1:-1]) * 1000000)
    return '${:d}'.format(millions)

>>> re.sub(r'\$\d+\.\d+m', sub_func, source)
'mr x is worth $44400000 and mr y is worth $59100000'

您可以使用'${:,d}'.format(millions)来获取,例如'$44,400,000'