Python正則表達式忽略兩個連續大寫字母的句子

我有一個簡單的問題，可以忽略包含兩個或多個連續大寫字母和更多語法規則的句子。Python正則表達式忽略兩個連續大寫字母的句子

問題：根據定義，正則表達式不應與字符串'This is something with two CAPS.'匹配，但它確實匹配。

代碼：

''' Check if a given sentence conforms to given grammar rules 

    $ Rules 
     * Sentence must start with a Uppercase character (e.g. Noun/ I/ We/ He etc.) 
     * Then lowercase character follows. 
     * There must be spaces between words. 
     * Then the sentence must end with a full stop(.) after a word. 
     * Two continuous spaces are not allowed. 
     * Two continuous upper case characters are not allowed. 
     * However the sentence can end after an upper case character. 
''' 

import re 


# Returns true if sentence follows these rules else returns false 
def check_sentence(sentence): 
    checker = re.compile(r"^((^(?![A-Z][A-Z]+))([A-Z][a-z]+)(\s\w+)+\.$)") 
    return checker.match(sentence) 

print(check_sentence('This is something with two CAPS.'))

輸出：

<_sre.SRE_Match object; span=(0, 32), match='This is something with two CAPS.'>

來源

2016-10-09 Aswin Mohan

它可能更容易編寫你的正則表達式中的負（發現是壞的句子所有句子），比它在正。

checker = re.compile(r'([A-Z][A-Z]|[ ][ ]|^[a-z])') 
check2 = re.compile(r'^[A-Z][a-z].* .*\.$') 
return not checker.findall(sentence) and check2.findall(sentence)

來源

2016-10-09 04:39:01 2ps

這是很難的，我有一個測試套件這裏是tha的結果t –

???結果@ aswin-mohan在哪裏？ – 2ps

更重要的是，它爲什麼難以工作？ – 2ps

您的負面預測僅適用於被測試字符串的開頭。

第二捕獲組(^(?![A-Z][A-Z]+))

^斷言位置在字符串的開始

負先行(?![A-Z][A-Z]+)

"This will NOT fail."

"THIS will fail."

來源

2016-10-09 04:47:06 sytech

謝謝。你能否寫下修改後的正則表達式？ –

Python正則表達式忽略兩個連續大寫字母的句子

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