使用正则表达式格式化文档

Question

我有一段文字是这样的-

Authority: soaplab.icapture.ubc.ca - EMBOSS seqret program. The sequence source is USA (Uniform Sequence Address). This means that you pass in a database name as the namespace.and an entry from the db as the id, e.g.db = embl and id = X13776. The input format is swiss.The output format is fasta.

使用正则表达式，我必须正确格式化文本-在句号后放置空格，只要句子长度（两个句号之间）超过7。给定文本中的一个示例是-例如db。。。和瑞士。输出格式是

我用下面的正则表达式来匹配这些句号-

\.[^\.]{7,}\.

例如

Input - The input format is swiss.The output format is fasta.
Output - The input format is swiss. The output format is fasta.

Input - from the db as the id, e.g.db = embl and id = X13776.
Output - from the db as the id, e.g. db = embl and id = X13776.

但是，这将匹配整个句子的长度为7或更大，而不是只有句号。我怎么才能只匹配我想要的两个箱子

Answer 1

可以在re.sub函数中使用捕获组或基于正向前瞻的正则表达式

>>> import re
>>> s = '''The input format is swiss.The output format is fasta.
from the db as the id, e.g.db = embl and id = X13776.'''
>>> print(re.sub(r'\.([^.]{7,}\.)', r'. \1', s))
The input format is swiss. The output format is fasta.
from the db as the id, e.g. db = embl and id = X13776.

[^.]{7,}匹配任何字符，但不匹配点，7次或更多次。所以在两个点之间至少有7个字符

---

>>> print(re.sub(r'\.(?=[^.]{7,}\.)', r'. ', s))
The input format is swiss. The output format is fasta. 
from the db as the id, e.g. db = embl and id = X13776.

\.(?=[^.]{7,}\.)仅当后跟至少有7个字符的句子时才匹配点。如果是，则用点+空格替换匹配的点

---

>>> print(re.sub(r'(?<=\.)(?=[^.]{7,}\.)', r' ', s))
The input format is swiss. The output format is fasta. 
from the db as the id, e.g. db = embl and id = X13776.