如何在正則表達式中捕獲子模式的所有重復

Question

我有一個格式化的字符串，它可以有任意長度的重復部分。 例如，這是我想要解析的元數據的示例。

File Name: chb03_34.edf
File Start Time: 01:51:23
File End Time: 2:51:23
Number of Seizures in File: 1
Seizure Start Time: 1982 seconds
Seizure End Time: 2029 seconds

File Name: chb23_07.edf
File Start Time: 11:03:16
File End Time: 11:45:56
Number of Seizures in File: 0

File Name: chb23_08.edf
File Start Time: 11:48:05
File End Time: 14:40:27
Number of Seizures in File: 2
Seizure 1 Start Time: 325 seconds
Seizure 1 End Time: 345 seconds
Seizure 2 Start Time: 5104 seconds
Seizure 2 End Time: 5151 seconds

File Name: chb23_09.edf
File Start Time: 14:40:47
File End Time: 18:41:13
Number of Seizures in File: 4
Seizure 1 Start Time: 2589 seconds
Seizure 1 End Time: 2660 seconds
Seizure 2 Start Time: 6885 seconds
Seizure 2 End Time: 6947 seconds
Seizure 3 Start Time: 8505 seconds
Seizure 3 End Time: 8532 seconds
Seizure 4 Start Time: 9580 seconds
Seizure 4 End Time: 9664 seconds

到目前為止，我已經創建了一個捕獲第一行的正則表達式，但只能捕獲最后一次捕獲（如果存在捕獲）在一個塊中。

import re

summary = "a formatted string read"


pattern = "File Name\: (.+)\nFile Start Time\: (.+)\nFile End Time\: (.+)\nNumber of Seizures in File\: (.+)(?:\n|\r|)(?:Seizure(?: | \d )Start Time\: (\d+) seconds\nSeizure(?: | \d )End Time\: (\d+) seconds(?:\n|\r|))*"
pattern = re.compile(pattern)

for p in pattern.finditer(summary):
    print(p.groups())

但是，例如最后一個塊的這種模式的結果只會捕獲 seizure 4 的開始和結束時間。 是否可以遞歸地捕獲重復的子模式？

編輯：使用regex和模式第四只鳥輸入了評論，我可以匹配字符串，但我在重復的行中得到了很多 None 值，而且完全沒有行。 我怎樣才能擺脫那些，或插入適當的價值？

('chb23_06.edf', '08:57:57', '11:02:43', '1', '3962', '4075')
(None, None, None, None, None, None)
('chb23_07.edf', '11:03:16', '11:45:56', '0', None, None)
(None, None, None, None, None, None)
('chb23_08.edf', '11:48:05', '14:40:27', '2', '325', '345')
(None, None, None, None, '5104', '5151')
(None, None, None, None, None, None)
('chb23_09.edf', '14:40:47', '18:41:13', '4', '2589', '2660')
(None, None, None, None, '6885', '6947')
(None, None, None, None, '8505', '8532')
(None, None, None, None, '9580', '9664')
(None, None, None, None, None, None)
('chb23_10.edf', '18:41:40', '22:41:40', '0', None, None)
(None, None, None, None, None, None)
('chb23_16.edf', '13:46:32', '17:46:32', '0', None, None)
(None, None, None, None, None, None)
('chb23_17.edf', '17:46:42', '21:16:29', '0', None, None)
(None, None, None, None, None, None)
('chb23_19.edf', '02:28:28', '6:28:28', '0', None, None)
(None, None, None, None, None, None)
('chb23_20.edf', '06:28:36', '7:52:05', '0', None, None)
(None, None, None, None, None, None)

EDIT2：我做了先前接受的答案的解決方案，但它有一些粗糙的邊緣並且在某些文件中不起作用。 我已經上傳了一個有問題的文件。 您可以在此處找到有問題的元數據示例的粘貼。

Answer 1

使用re ，您可以捕獲一組中 Seizure 字符串的可選迭代，然后從該組中捕獲秒數的數字值：

圖案

File Name: (.+)\nFile Start Time: (.+)\nFile End Time: (.+)\nNumber of Seizures in File: (.+)((?:\nSeizure (?:\d )?Start Time: \d+ seconds\nSeizure (?:\d )?End Time: \d+ seconds)*)

模式匹配：

• File Name: (.+)\n Group 1 ，匹配 File Name: 之后的所有內容和一個換行符
• File Start Time: (.+)\n Group 2 ，匹配 File Start Time: 之后的所有內容和換行符
• File End Time: (.+)\n Group 3 ，匹配 File End Time: 之后的所有內容和一個換行符
• Number of Seizures in File: (.+) Group 4 ，在文件中的癲癇發作次數之后匹配所有：
• (第 5 組
  • (?:非捕獲組作為一個整體進行匹配，然后可選地重復
    • \nSeizure (?:\d )?Start Time: \d+ seconds\n匹配一個換行符匹配Seizure Start Time和結尾的一個換行符
    • Seizure (?:\d )?End Time: \d+ seconds匹配癲癇發作結束時間
  • )*關閉非捕獲組並有選擇地重復它
• )關閉組 5

正則表達式演示| Python 演示

例如

pattern = re.compile(pattern)

for m in pattern.finditer(summary):
    print(m.group(1))
    print(m.group(2))
    print(m.group(3))
    print(m.group(4))
    print(re.findall(r"(\d+) seconds", m.group(5)))

每場比賽的 output 看起來像：（或者當沒有 Seizure 值時是一個空列表，但您也可以對其進行測試）

chb23_08.edf
11:48:05
14:40:27
2
['325', '345', '5104', '5151']

Answer 2

如果您使用的是正則表達式模塊，我建議您使用重復捕獲。

為了清楚起見，我還添加了命名組：

import regex

pattern = regex.compile(
    r"File Name: (?P<name>.+)\n"
    r"File Start Time: (?P<start>.+)\n"
    r"File End Time: (?P<end>.+)\n"
    r"Number of Seizures in File: (?P<count>\d+)\n"
    r"(?:\n|(?:Seizure (?:\d )?Start Time: (?P<seizure_start>\d+) seconds\n"
    r"Seizure (?:\d )?End Time: (?P<seizure_end>\d+) seconds\n)*)"
)

summary = """File Name: chb03_34.edf
File Start Time: 01:51:23
File End Time: 2:51:23
Number of Seizures in File: 1
Seizure Start Time: 1982 seconds
Seizure End Time: 2029 seconds

File Name: chb23_07.edf
File Start Time: 11:03:16
File End Time: 11:45:56
Number of Seizures in File: 0

File Name: chb23_08.edf
File Start Time: 11:48:05
File End Time: 14:40:27
Number of Seizures in File: 2
Seizure 1 Start Time: 325 seconds
Seizure 1 End Time: 345 seconds
Seizure 2 Start Time: 5104 seconds
Seizure 2 End Time: 5151 seconds

File Name: chb23_09.edf
File Start Time: 14:40:47
File End Time: 18:41:13
Number of Seizures in File: 4
Seizure 1 Start Time: 2589 seconds
Seizure 1 End Time: 2660 seconds
Seizure 2 Start Time: 6885 seconds
Seizure 2 End Time: 6947 seconds
Seizure 3 Start Time: 8505 seconds
Seizure 3 End Time: 8532 seconds
Seizure 4 Start Time: 9580 seconds
Seizure 4 End Time: 9664 seconds
"""

for match in pattern.finditer(summary):
    print("Name:", match.group("name"))
    print("Seizure Count", match.group("count"))
    seizures = tuple(
        zip(match.captures("seizure_start"),match.captures("seizure_end")))
    for i, (start, end) in enumerate(seizures, start=1):
        print(f"Seizure #{i}: {start} -> {end}")

印刷：

Name: chb03_34.edf
Seizure Count 1
Seizure #1: 1982 -> 2029
Name: chb23_07.edf
Seizure Count 0
Name: chb23_08.edf
Seizure Count 2
Seizure #1: 325 -> 345
Seizure #2: 5104 -> 5151
Name: chb23_09.edf
Seizure Count 4
Seizure #1: 2589 -> 2660
Seizure #2: 6885 -> 6947
Seizure #3: 8505 -> 8532
Seizure #4: 9580 -> 9664