如何在Python中读取字符串的一部分并存储到列表中

Question

我在 python 中有一个字符串变量，我需要提取以特定字符串开头和结尾的所有部分。

开始字符串是“proc sql”，结束字符串是“quit;”之间的所有行都应提取到列表中；

row ='''proc sql;
        create table answer_1_stg1 as 
        select  distinct a.CUSTOMER_HIERARCHY_LVL2_CD
                ,b.brand_cd
                ,b.category_cd
                ,a.promo_mechanic_nm
                ,a.promo_mechanic_desc
                ,sum(b.invoice_qty) as sum_invoice
                ,avg(b.invoice_qty) as avg_invoice
                ,max(b.invoice_qty) as max_invoice
                ,min(b.invoice_qty) as min_invoice
        from promo as a
        left join invoice as b
        on 
        a.CUSTOMER_HIERARCHY_LVL2_CD=b.CUSTOMER_HIERARCHY_LVL2_CD and
        a.basecode=b.basecode and
        a.SALESORG_CD=b.SALESORG_CD and
        a.LOCATION_CD=b.LOCATION_CD
        and b.INVOICE_DT between a.event_start_dt and a.event_end_dt
        where year(a.event_start_dt) = 2017 and year(b.INVOICE_DT) = 2017
        group by a.CUSTOMER_HIERARCHY_LVL2_CD
                ,b.brand_cd
                ,b.category_cd
                ,a.promo_mechanic_nm
                ,a.promo_mechanic_desc;
        quit;
        
%sort(answer_1_stg1,descending sum_invoice);

proc sql;
create table answer_1_stg2 as
select distinct promo_mechanic_desc
        ,sum(sum_invoice) as total
from answer_1_stg1;
quit;'''

我只需要提取两个字符串“proc sql”和“quit”之间的部分。最终的列表应该是这样的：

lt = ['''proc sql;
        create table answer_1_stg1 as 
        select  distinct a.CUSTOMER_HIERARCHY_LVL2_CD
                ,b.brand_cd
                ,b.category_cd
                ,a.promo_mechanic_nm
                ,a.promo_mechanic_desc
                ,sum(b.invoice_qty) as sum_invoice
                ,avg(b.invoice_qty) as avg_invoice
                ,max(b.invoice_qty) as max_invoice
                ,min(b.invoice_qty) as min_invoice
        from promo as a
        left join invoice as b
        on 
        a.CUSTOMER_HIERARCHY_LVL2_CD=b.CUSTOMER_HIERARCHY_LVL2_CD and
        a.basecode=b.basecode and
        a.SALESORG_CD=b.SALESORG_CD and
        a.LOCATION_CD=b.LOCATION_CD
        and b.INVOICE_DT between a.event_start_dt and a.event_end_dt
        where year(a.event_start_dt) = 2017 and year(b.INVOICE_DT) = 2017
        group by a.CUSTOMER_HIERARCHY_LVL2_CD
                ,b.brand_cd
                ,b.category_cd
                ,a.promo_mechanic_nm
                ,a.promo_mechanic_desc;
        quit;''','''proc sql;
create table answer_1_stg2 as
select distinct promo_mechanic_desc
        ,sum(sum_invoice) as total
from answer_1_stg1;
quit;''']

我尝试运行以下代码，但它只将第一行打印到列表中：

fm = []

for i in row.split('\n'):
    if "proc sql" in i:
        print()
        fm.append(i.strip())

Answer 1

您需要额外的变量来控制您是否在

proc sql

和

quit

之间

循环设置之前，即

found = False

， 循环中

• 当你找到

  proc sql

  然后设置

  found = True

  （并设置为空

  fm

  ）
• 下次使用

  if found: fm.append(i)

• 当你找到

  quit

  然后设置

  found = False

  （并将

  fm

  转换为字符串，并添加到

  lt

  ）

row ='''proc sql;
        create table answer_1_stg1 as 
        select  distinct a.CUSTOMER_HIERARCHY_LVL2_CD
                ,b.brand_cd
                ,b.category_cd
                ,a.promo_mechanic_nm
                ,a.promo_mechanic_desc
                ,sum(b.invoice_qty) as sum_invoice
                ,avg(b.invoice_qty) as avg_invoice
                ,max(b.invoice_qty) as max_invoice
                ,min(b.invoice_qty) as min_invoice
        from promo as a
        left join invoice as b
        on 
        a.CUSTOMER_HIERARCHY_LVL2_CD=b.CUSTOMER_HIERARCHY_LVL2_CD and
        a.basecode=b.basecode and
        a.SALESORG_CD=b.SALESORG_CD and
        a.LOCATION_CD=b.LOCATION_CD
        and b.INVOICE_DT between a.event_start_dt and a.event_end_dt
        where year(a.event_start_dt) = 2017 and year(b.INVOICE_DT) = 2017
        group by a.CUSTOMER_HIERARCHY_LVL2_CD
                ,b.brand_cd
                ,b.category_cd
                ,a.promo_mechanic_nm
                ,a.promo_mechanic_desc;
        quit;
        
%sort(answer_1_stg1,descending sum_invoice);

proc sql;
create table answer_1_stg2 as
select distinct promo_mechanic_desc
        ,sum(sum_invoice) as total
from answer_1_stg1;
quit;'''

found = False

lt = []
fm = []

for line in row.split('\n'):
    line = line.strip()
    if "proc sql" in line:
        found = True
        fm = []
    if found:
        fm.append(line)
    if "quit" in line:
        found = False
        lt.append( "\n".join(fm) )
      
for item in lt:
    print(item)
    print('----')