[英]Regular expression to capture a group of words followed by a group of formatted quantities
給定文本文件的內容(如下),我想從具有以下模式的每一行中提取兩個值 - 用[#]指示的捕獲組:
目標是捕獲文本中“Notes”和“2019”列下的值並將它們放入Python字典中。
我嘗試使用以下正則表達式:
(\\w+)\\s{1}(\\w+)*
(.*?)[ ]{2,}(.*?)[ ]{2,}(.*?)[ ]{2,}(.*)
示例文本文件:
Micro-entity Balance Sheet as at 31 May 2019
Notes 2019 2018
£ £
Fixed Assets 2,046 1,369
Current Assets 53,790 24,799
Creditors: amounts falling due within one year (23,146) (6,106)
Net current assets (liabilities) 30,644 18,693
Total assets less current liabilities 32,690 20,062
Total net assets (liabilities) 32,690 20,062
Capital and reserves 32,690 20,062
For the year ending 31 May 2019 the company was entities to exemption under section 477 of the
Companies Act 2006 relating to small companies
® The members have not required the company to obtain an audit in accordance with section 476 of
the Companies Act 2006.
® The director acknowledge their responsibilities for complying with the requirements of the
Companies Act 2006 with respect to accounting records and the preparation of accounts.
® The accounts have been prepared in accordance with the micro-entity provisions and delivered in
accordance with the provisions applicable to companies subject to the small companies regime.
Approved by the Board on 20 December 2019
And signed on their behalf by:
Director
This document was delivered using electronic communications and authenticated in accordance with the
registrar's rules relating to electronic form, authentication and manner of delivery under section 1072 of
the Companies Act 2006.
示例有效匹配:
"Fixed Assets", "2,046"
"Current Assets", "53,790"
"Creditors: amounts falling due within one year", "(23,146)"
"Net current assets (liabilities)", "30,644"
"Total assets less current liabilities", "32,690"
"Total net assets (liabilities)", "32,690"
"Capital and reserves", "32,690"
你的第一個正則表達式…
(\w+)\s{1}(\w+)*
... 是不夠的,因為兩個捕獲組沒有考慮第一種情況下單詞之間的空格或第二種情況下的數量格式。
你的第二個正則表達式……
(.*?)[ ]{2,}(.*?)[ ]{2,}(.*?)[ ]{2,}(.*)
...更好,因為它有效地捕獲了詞組,無論多么急切。
筆記:
- 您不需要圍繞前導和尾隨空格的捕獲組。
- 空格字符周圍不需要括號。 括號表示一組字符,但您在該組中只有一個字符。
如果您通過刪除不必要的捕獲組稍微修改它......
.*? {2,}(.*?) {2,}(.*?) {2,}.*
…您可以看到它捕獲了“Notes”和“2019”下的值,但它也積極地捕獲了不需要的文本。
您可以解析這些匹配項並使用 Python 代碼丟棄不需要的匹配項。 您不需要正則表達式,但可以更精確地使用它。
您的正則表達式捕獲了不需要的數據,因為您不必要地將任何字符與.*?
,當您實際上想要將匹配限制為:
只有您關心的線條才真正遵循此模式。
考慮一下:
^ *((?:\S+ )+) {2,}(\(?[0-9,]+\)?).*$
上述正則表達式通過以下方式改進了模式匹配:
^
和行尾$
以防止匹配多行。(?:\\S+ )+
\\S
匹配以捕獲“單詞”和標點符號(例如:
)。\\(?[0-9,]+\\)?
但即使這樣也會返回不需要的列標題“Notes”和“2019”。 您可以使用否定前瞻... (?!Notes)
...來防止匹配包含“Notes”的行。
最終解決方案:
^ *((?:(?!Notes)\S+ )+) {2,}((?[0-9,]+)?).*$
查看@ Regex101.com
您可能會發現將其視為語法圖很有教育意義: 查看@ RegExper.com
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