如何找到文本中匹配的单词的索引?

时间:2018-09-03 11:01:32

标签: python regex regex-group

我正在提取this regex中匹配的单词的索引。它使用正则表达式匹配文本中所有必需的单词,但也匹配正则表达式的剩余空间。它不是在左侧文本中限制匹配的字符串,而是使用\b

来限制匹配字符串的右侧。

正则表达式:

(price|rs)?\s*(\d+[\s\d.]*\s*?(pkg|k|m|(?:la(?:c|kh|k)|crore|cr)s?|l)\b\.?)

输入文字:

    This should matchprice  5.6 lacincluding price(i.e  price 5.6 lac) and rs 56 m. including rs (i.e rs 56 k  rs 56 m) .

It will match normally if there is no price or rs written for example or                   56 k or   8.8 crs.   are  correct matching but its should bound the matched string from left side as well just like its not matching sapce after end of the matched string.

It should not match the spaces left of 8.5 in this      8.5 lac ould not match eitherrs 6 lac asas there is no spaces before 5.6

How can I modify above regex to bound the matched word in the left side as well? 

1 个答案:

答案 0 :(得分:2)

您可以将\s*移至可选的非捕获组:

(?:\b(price|rs)\s*)?(\d+[\s\d.]*\s*?(pkg|k|m|(?:la(?:c|kh|k)|crore|cr)s?|l)\b\.?)
^^^^^^^^^^^^^^^^^^^^

请参见regex demo

(?:\b(price|rs)\s*)?模式将匹配单词边界,后跟pricers,后跟0+个空格字符,整个模式将尝试一次,并且该模式由于?修饰符是可选的(整个模式序列可以匹配1或0次)