使用：

import re

sequence = "AGATCAGATCTTTTTTCTAATGTCTAGGATATATCAGATCAGATCAGATCAGATCAGATC"
matches = re.findall(r'(?:AGATC)+', sequence)

# To find the longest subsequence
longest = max(matches, key=len)

说明：

非捕获组（?: AGATC）+

• + 量词-一次和无限次匹配，例如


• AGATC 字面上匹配字符AGATC（区分大小写）

• + Quantifier — Matches between one and unlimited times, as many times as possible.
• AGATC matches the characters AGATC literally (case sensitive)

结果：

# print(matches)
['AGATCAGATC', 'AGATCAGATCAGATCAGATCAGATC']

# print(longest)
'AGATCAGATCAGATCAGATCAGATC'

您可以测试正则表达式 此处 。

You can test the regex here.