I am trying to make a small application which uses pyparsing
to extract data from files produced by another program.
These files have following format.<
This takes you most of the way there:
import pyparsing as pp
data = """
SOME_KEYWORD:
line 1
line 2
line 3
line 4
ANOTHER_KEYWORD:
line a
line b
line c
"""
some_kw = pp.Keyword('SOME_KEYWORD:').suppress()
another_kw = pp.Keyword('ANOTHER_KEYWORD:').suppress()
kw = pp.Optional(some_kw ^ another_kw)
# Hint from: http://pyparsing.wikispaces.com/message/view/home/21931601
lines = kw + pp.SkipTo(
pp.LineEnd() + pp.OneOrMore(pp.LineEnd()) |
pp.LineEnd() + pp.StringEnd() |
pp.StringEnd()
)
result = lines.searchString(data.strip())
results_list = result.asList()
# => [['\nline 1\nline 2\nline 3\nline 4'], ['\nline a\nline b\nline c']]
When building a grammar it really helps to assign parts to variables and reference those when you can.
My take on it:
from pyparsing import *
# matches and removes end of line
EOL = LineEnd().suppress()
# line starts, anything follows until EOL, fails on blank lines,
line = LineStart() + SkipTo(LineEnd(), failOn=LineStart()+LineEnd()) + EOL
lines = OneOrMore(line)
# Group keyword probably helps grouping these items together, you can remove it
parser = Keyword("SOME_KEYWORD:") + EOL + Group(lines) + Keyword("ANOTHER_KEYWORD:") + EOL + Group(lines)
result = parser.parseFile('data.txt')
print result
Result is:
['SOME_KEYWORD:', ['line 1', 'line 2', 'line 3', 'line 4'], 'ANOTHER_KEYWORD:', ['line a', 'line b', 'line c']]