我正在研究一个项目，该项目涉及以某种格式创建美国联邦代码数据库。我获得了整个代码形式的官方资源，该来源的结构不佳。我设法使用github上的某些代码将以下格式刮擦到文本文件中。
。-CITE-
13 USC Sec. 1 1/15/2013
-EXPCITE-
TITLE 13 - CENSUS
CHAPTER 1 - ADMINISTRATION
SUBCHAPTER I - GENERAL PROVISIONS
-HEAD-
Sec. 1. Definitions
-STATUTE-
As used in this title, unless the context requires another
meaning or unless it is otherwise provided -
(1) "Bureau" means the Bureau of the Census;
(2) "Secretary" means the Secretary of Commerce; and
(3) "respondent" includes a corporation, company, association,
firm, partnership, proprietorship, society, joint stock company,
individual, or other organization or entity which reported
information, or on behalf of which information was reported, in
response to a questionnaire, inquiry, or other request of the
Bureau.
-SOURCE-
(Aug. 31, 1954, ch. 1158, 68 Stat. 1012; Pub. L. 94-521, Sec. 1,
Oct. 17, 1976, 90 Stat. 2459.)
-MISC1-
<some text>
-End-
-CITE-
13 USC Sec. 2 1/15/2013
-EXPCITE-
TITLE 13 - CENSUS
CHAPTER 1 - ADMINISTRATION
SUBCHAPTER I - GENERAL PROVISIONS
-HEAD-
Sec. 2. Bureau of the Census
-STATUTE-
The Bureau is continued as an agency within, and under the
jurisdiction of, the Department of Commerce.
-SOURCE-
(Aug. 31, 1954, ch. 1158, 68 Stat. 1012.)
-MISC1-
<some text>
-End-
每个文本文件包含以-cite -tag开头的数千个这样的块，并以-End-结尾。
除此之外，还有某些代表章节或子章的开始，而这些块不包含-statute- tag。
例如。
-CITE-
13 USC CHAPTER 3 - COLLECTION AND PUBLICATION OF
STATISTICS 1/15/2013
-EXPCITE-
TITLE 13 - CENSUS
CHAPTER 3 - COLLECTION AND PUBLICATION OF STATISTICS
-HEAD-
CHAPTER 3 - COLLECTION AND PUBLICATION OF STATISTICS
-MISC1-
SUBCHAPTER I - COTTON
Sec.
41. Collection and publication.
42. Contents of reports; number of bales of linter;
distribution; publication by Department of
Agriculture.
43. Records and reports of cotton ginners.
SUBCHAPTER II - OILSEEDS, NUTS, AND KERNELS; FATS, OILS, AND
GREASES
61. Collection and publication.
62. Additional statistics.
63. Duplicate collection of statistics prohibited; access
to available statistics.
SUBCHAPTER III - APPAREL AND TEXTILES
81. Statistics on apparel and textile industries.
SUBCHAPTER IV - QUARTERLY FINANCIAL STATISTICS
91. Collection and publication.
SUBCHAPTER V - MISCELLANEOUS
101. Defective, dependent, and delinquent classes; crime.
102. Religion.
103. Designation of reports.
AMENDMENTS
<some text>
-End-
我只对那些具有-statute -tag的块感兴趣。
是否有一种方法仅提取具有-statute-标签的文本块并将其写入另一个文本文件？
我是Python的新手
感谢有人可以指导我。
因此，对于每一行，如果它以连字符开头，然后是一些上案例文本，然后是另一个连字符，然后是一个标记，指出我们正在新的某种部分。这可以使用正则表达式完成：
current_section_type = None
r= re.compile("^-([A-Z]*)-")
for line in f.readlines():
m=r.match(line)
if m:
current_section_type = m.group(1)
else:
if current_section_type == "STATUTE":
print line.strip()
我会逐行阅读文本行，然后自己解析。这样，您可以处理大型输入作为流。使用多行左右有更好的解决方案，但这些解决方案总是无法将输入作为流进行处理。
#!/usr/bin/env python
import sys, re
# states for our state machine:
OUTSIDE = 0
INSIDE = 1
INSIDE_AFTER_STATUTE = 2
def eachCite(stream):
state = OUTSIDE
for lineNumber, line in enumerate(stream):
if state in (INSIDE, INSIDE_AFTER_STATUTE):
capture += line
if re.match('^-CITE-', line):
if state == OUTSIDE:
state = INSIDE
capture = line
elif state in (INSIDE, INSIDE_AFTER_STATUTE):
raise Exception("-CITE- in -CITE-??", lineNumber)
else:
raise NotImplementedError(state)
elif re.match('^-End-', line):
if state == OUTSIDE:
raise Exception("-End- without -CITE-??", lineNumber)
elif state == INSIDE:
yield False, capture
state = OUTSIDE
elif state == INSIDE_AFTER_STATUTE:
yield True, capture
state = OUTSIDE
else:
raise NotImplementedError(state)
elif re.match('^-STATUTE-', line):
if state == OUTSIDE:
raise Exception("-STATUTE- without -CITE-??", lineNumber)
elif state == INSIDE:
state = INSIDE_AFTER_STATUTE
elif state == INSIDE_AFTER_STATUTE:
raise Exception("-STATUTE- after -STATUTE-??", lineNumber)
else:
raise NotImplementedError(state)
if state != OUTSIDE:
raise Exception("EOF in -CITE-??")
for withStatute, cite in eachCite(sys.stdin):
if withStatute:
print "found cite with statute:"
print cite
如果您不需要处理sys.stdin，则可以这样做：
with open('myInputFileName') as myInputFile,
open('myOutputFileName', 'w') as myOutputFile:
for withStatute, cite in eachCite(myInputFile):
if withStatute:
myOutputFile.write("found cite with statute:n")
myOutputFile.write(cite)