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匹配多行文本块的正则表达式

multiline regex python

154

Jan · 技术社区 · 17 年前

\n 是换行符)

some Varying TEXT\n
\n
DSJFKDAFJKDAFJDSAKFJADSFLKDLAFKDSAF\n
[more of the above, ending with a newline]\n
[yep, there is a variable number of lines here]\n
\n
(repeat the above a few hundred times).

我想捕捉两件事:

这 some Varying TEXT
capture(我稍后可以去掉换行符)。

re.compile(r"^>(\w+)$$([.$]+)^$", re.MULTILINE) # try to capture both parts
re.compile(r"(^[^>][\w\s]+)$", re.MULTILINE|re.DOTALL) # just textlines

…还有很多变体,但运气不佳。最后一个似乎与文本行一一匹配,这不是我真正想要的。我可以抓住第一部分,没问题,但我似乎无法抓住4-5行大写文本。 match.group(1) some Varying Text 和 group(2) 直到遇到空行为止。

如果有人好奇,它应该是构成蛋白质的氨基酸序列。

7 回复 | 直到 3 年前

134

Alan Moore Chris Ballance 5 年前

试试这个:

re.compile(r"^(.+)\n((?:\n.+)+)", re.MULTILINE)

^ 和 $ 立即匹配位置立即匹配位置换行符。

还要注意,换行符可以由换行符组成( \n \r \r\n

re.compile(r"^(.+)(?:\n|\r\n?)((?:(?:\n|\r\n?).+)+)", re.MULTILINE)

顺便说一句,你不想在这里使用DOTALL修饰符;你所依赖的事实是,这个点与所有东西都匹配

MiniQuark 17 年前

>>> import re
>>> rx_sequence=re.compile(r"^(.+?)\n\n((?:[A-Z]+\n)+)",re.MULTILINE)
>>> rx_blanks=re.compile(r"\W+") # to remove blanks and newlines
>>> text="""Some varying text1
...
... AAABBBBBBCCCCCCDDDDDDD
... EEEEEEEFFFFFFFFGGGGGGG
... HHHHHHIIIIIJJJJJJJKKKK
...
... Some varying text 2
...
... LLLLLMMMMMMNNNNNNNOOOO
... PPPPPPPQQQQQQRRRRRRSSS
... TTTTTUUUUUVVVVVVWWWWWW
... """
>>> for match in rx_sequence.finditer(text):
...   title, sequence = match.groups()
...   title = title.strip()
...   sequence = rx_blanks.sub("",sequence)
...   print "Title:",title
...   print "Sequence:",sequence
...   print
...
Title: Some varying text1
Sequence: AAABBBBBBCCCCCCDDDDDDDEEEEEEEFFFFFFFFGGGGGGGHHHHHHIIIIIJJJJJJJKKKK

Title: Some varying text 2
Sequence: LLLLLMMMMMMNNNNNNNOOOOPPPPPPPQQQQQQRRRRRRSSSTTTTTUUUUUVVVVVVWWWWWW

^(.+?)\n\n((?:[A-Z]+\n)+)

^
(.+?)\n\n 意思是“尽可能少地匹配字符(允许所有字符),直到达到两个新行”。结果(不含换行符)被放入第一组。
[A-Z]+\n 意思是“在换行之前,尽可能多地匹配大写字母。这定义了我所说的 .
((?: )+) 指匹配一个或多个但不要把每一行都放在一个组中。相反,把这
你可以添加一个final \n
此外,如果你不确定你会得到什么类型的换行符( n 或 \r 或 \r\n n (?:\n|\r\n?) .

Grant Miller 7 年前

import re
result = re.findall('(startText)(.+)((?:\n.+)+)(endText)',input)

MiniQuark 17 年前

def read_amino_acid_sequence(path):
    with open(path) as sequence_file:
        title = sequence_file.readline() # read 1st line
        aminoacid_sequence = sequence_file.read() # read the rest

    # some cleanup, if necessary
    title = title.strip() # remove trailing white spaces and newline
    aminoacid_sequence = aminoacid_sequence.replace(" ","").replace("\n","")
    return title, aminoacid_sequence

Jason Coon 17 年前

有时,直接在字符串中指定标志会很舒服,因为 inline-flag :

"(?m)^A complete line$".

assertRaisesRegex 那样的话,你就不需要了 import re

S.Lott 17 年前

^>([^\n\r]+)[\n\r]([A-Z\n\r]+)

\2=所有CAPS的行数

编辑(证明这有效):

text = """> some_Varying_TEXT

DSJFKDAFJKDAFJDSAKFJADSFLKDLAFKDSAF
GATACAACATAGGATACA
GGGGGAAAAAAAATTTTTTTTT
CCCCAAAA

> some_Varying_TEXT2

DJASDFHKJFHKSDHF
HHASGDFTERYTERE
GAGAGAGAGAG
PPPPPAAAAAAAAAAAAAAAP
"""

import re

regex = re.compile(r'^>([^\n\r]+)[\n\r]([A-Z\n\r]+)', re.MULTILINE)
matches = [m.groups() for m in regex.finditer(text)]
#NOTE can be sorter with matches = re.findall(pattern, text, re.MULTILINE)

for m in matches:
    print 'Name: %s\nSequence:%s' % (m[0], m[1])