给出了约5000个HTML文档的非常大的文本文件。我试图“搜索”特定DOCNO的文本文件并打印文件的所有行，直到遇到下一个</DOC>标记。
文本文件大致如下：
<DOC>
<DOCNO>abc4567890</DOCNO>
contents
more contents
<BODY>
even more contents
</BODY>
</DOC>
... repeated roughly 5000 times for different DOC NO's
我正在寻找输出：
contents
more contents
<BODY>
even more contents
</BODY>
</DOC>
这是我一直试图实现的：
doc_string = "abc4567890"
with open('myfile.txt', encoding = "utf8") as f:
for item in f.readlines():
if "</DOCNO>" in item:
ID = (item [ item.find("<DOCNO>")+len("<DOCNO>") : ])
if (ID[0:9] == doc_string):
print (item)
if "</DOC>" in item:
break
但是，作为输出，我得到：
<DOCNO>abc4567890</DOCNO>
# initialize variables:
lines = []
read_lines = False
with open('file.txt', 'r') as file:
# iterate over each line:
for line in file.readlines():
# append line to lines list:
if read_lines: lines.append(line)
# set read_lines to True:
if '</DOCNO>' in line: read_lines = True
# set read_lines to False:
if '</DOC>' in line: read_lines = False
# print each line:
for line in lines:
print(line, end='')
给出您的输入，它将输出：
contents
more contents
<BODY>
even more contents
</BODY>
</DOC>