使用 Python re 提取多行字符串的特定部分

Question

我一直在尝试在多行文本中提取 SQL 查询，但我一直得到错误的输出。

如何获取一个或三个引号之间的文本？

注意：第一个完整引号 ''、""、""""""、'''''' 前后可以有任何内容，我只对查找之间的第一个文本感兴趣引号。

import re

cell_text = """\
#%%sql
q = \"\"\"
select 
name, breed, sum(weight) over (partition by breed order by name) as running_total_weight
from cats 
order by breed, name
\"\"\"

f(q)
"""
print(cell_text)

我的尝试：

pat = """.*select(.*)['"].*"""
out = re.findall(pat,cell_text,flags=re.M)[0]
sql = 'select ' + out
print(sql)

# I am getting empty outputs for re.findall instead of text there.

所需输出：

input
----

#%%sql
q = """
select 
name, breed, sum(weight) over (partition by breed order by name) as running_total_weight
from cats 
order by breed, name
"""

f(q)

output
------

select 
name, breed, sum(weight) over (partition by breed order by name) as running_total_weight
from cats 
order by breed, name


input
-----
#%%sql
q = "select * from cats;"

f(q)

output
-------
select * from cats;

input
-----
q = 'select * from cats limit 2'

output
------
select * from cats limit 2

Answer 1

您需要像这样使用DOTALL或(?s)模式：

>>> print (re.findall(r'(?s)"""(.*?)"""', cell_text)[0])

select
name, breed, sum(weight) over (partition by breed order by name) as running_total_weight
from cats
order by breed, name

您也可以在 re.findall:

中使用 flags 参数

re.findall(r'"""(.*?)"""', cell_text, flags=re.DOTALL)

编辑： 请注意，要匹配所有单引号或三引号文本，您可以交替使用此正则表达式：

r"""\"\"\"(.*?)\"\"\"|'''(.*?)'''|"(.*?)"|'(.*?)'"""

RegEx Demo

使用 Python re 提取多行字符串的特定部分

Extract certain portion of multiline string using Python re

python

regex

python-re