python - 使用组合解析文本不返回任何结果

Question

我是 pyparsing 新手。我正在尝试解析一些文本，但并不真正理解 pyparsing 的行为方式。

from pyparsing import *

number = Word(nums)
yearRange = Combine(number+"-"+number)
copyright = Literal("Copyright (C)")+yearRange+Literal("CA. All Rights Reserved.")
copyrightCombine = Combine(copyright)
date = Combine(Word(nums)+"/"+Word(nums)+"/"+Word(nums))
time = Combine(Word(nums)+":"+Word(nums)+":"+Word(nums))
dateTime = Combine(date+time)
pageNumber = Suppress(Literal("PAGE"))+number
pageLine = Word(nums)+"Copyright (C) 1986-2014 CA. All Rights Reserved."+Combine(Word(nums)+"/"+Word(nums)+"/"+Word(nums))+Combine(Word(nums)+":"+Word(nums)+":"+Word(nums))+pageNumber
pageLine2 = number+copyright+dateTime+pageNumber
pageLine3 = Word(nums)+copyright+Combine(Word(nums)+"/"+Word(nums)+"/"+Word(nums))+Combine(Word(nums)+":"+Word(nums)+":"+Word(nums))+pageNumber

test = "1  Copyright (C) 1986-2014 CA. All Rights Reserved.                                                07/05/17  10:58:56     PAGE  1241"
print(pageLine.searchString(test))
print(copyright.searchString(test))
print(copyrightCombine.searchString(test))
print(pageLine2.searchString(test))
print(pageLine3.searchString(test))

输出:

[['1', 'Copyright (C) 1986-2014 CA. All Rights Reserved.', '07/05/17', '10:58:56', '1241']]
[['Copyright (C)', '1986-2014', 'CA. All Rights Reserved.']]
[]
[]
[['1', 'Copyright (C)', '1986-2014', 'CA. All Rights Reserved.', '07/05/17', '10:58:56', '1241']]

我想使用定义为 pageLine2 的解析器，由于某种原因解析器copyrightCombine 没有返回任何结果。似乎当我尝试使用组合()时，某些原因导致解析不返回匹配项。

Answer 1

我发现这种行为的发生是由于 Combine() 的工作方式造成的。它期望 token 之间不会有任何空格，但可以被覆盖。

根据the documentation :

Combine - joins all matched tokens into a single string, using specified joinString (default joinString=""); expects all matching tokens to be adjacent, with no intervening whitespace (can be overridden by specifying adjacent=False in constructor)