Python 3.x Pyparsing正在查找比预期更多的匹配项

我正在写代码来解析基本的计算机指令行。我的输入字符串是这样的

ADD（input1，input2）DEL（input3），SUB（input1，input2）INS（input3）

我期待的结果是：

<line>
  <instruction>
    <type>ADD</type>
    <args>
      <ITEM>input1</ITEM>
      <ITEM>input2</ITEM>
    </args>
  </instruction>
  <instruction>
    <type>DEL</type>
    <args>
      <ITEM>input3</ITEM>
    </args>
  </instruction>
</line>
<line>
  <instruction>
    <type>SUB</type>
    <args>
      <ITEM>input1</ITEM>
      <ITEM>input2</ITEM>
    </args>
  </instruction>
  <instruction>
    <type>INS</type>
    <args>
      <ITEM>input3</ITEM>
    </args>
  </instruction>
</line>

出于某种原因，行在整个结构上匹配，第二行指令作为单个指令组匹配。我尝试在

指令

行上使用

.setDebug（）

函数，但是我不确定如何解释输出。我不明白为什么最后一行应该作为指令匹配，因为它不遵循单词（Word）模式

我的代码：

#!python3
from pyparsing import nestedExpr,alphas,Word,Literal,OneOrMore,alphanums,delimitedList,Group,Forward

theInput = r"ADD(input1,input2) DEL(input3), SUB(input1,input2) INS(input3)"

instructionType = Word(alphanums+"_")("type")
argument = Word(alphanums+"_[].")
arguments = Group(delimitedList(argument))("args")
instruction = Group(instructionType + Literal("(").suppress() + arguments + Literal(")").suppress())("instruction")

line = (delimitedList(Group(OneOrMore(instruction))))("line")

parsedInput = line.parseString(theInput).asXML()
print(parsedInput)

调试输出：

Match Group:({W:(ABCD...) Suppress:("(") Group:(W:(ABCD...) [, W:(ABCD...)]...) Suppress:(")")}) at loc 0(1,1)
Matched Group:({W:(ABCD...) Suppress:("(") Group:(W:(ABCD...) [, W:(ABCD...)]...) Suppress:(")")}) -> [['ADD', ['input1', 'input2']]]
Match Group:({W:(ABCD...) Suppress:("(") Group:(W:(ABCD...) [, W:(ABCD...)]...) Suppress:(")")}) at loc 18(1,19)
Matched Group:({W:(ABCD...) Suppress:("(") Group:(W:(ABCD...) [, W:(ABCD...)]...) Suppress:(")")}) -> [['DEL', ['input3']]]
Match Group:({W:(ABCD...) Suppress:("(") Group:(W:(ABCD...) [, W:(ABCD...)]...) Suppress:(")")}) at loc 30(1,31)
Exception raised:Expected W:(ABCD...) (at char 30), (line:1, col:31)
Match Group:({W:(ABCD...) Suppress:("(") Group:(W:(ABCD...) [, W:(ABCD...)]...) Suppress:(")")}) at loc 32(1,33)
Matched Group:({W:(ABCD...) Suppress:("(") Group:(W:(ABCD...) [, W:(ABCD...)]...) Suppress:(")")}) -> [['SUB', ['input1', 'input2']]]
Match Group:({W:(ABCD...) Suppress:("(") Group:(W:(ABCD...) [, W:(ABCD...)]...) Suppress:(")")}) at loc 50(1,51)
Matched Group:({W:(ABCD...) Suppress:("(") Group:(W:(ABCD...) [, W:(ABCD...)]...) Suppress:(")")}) -> [['INS', ['input3']]]
Match Group:({W:(ABCD...) Suppress:("(") Group:(W:(ABCD...) [, W:(ABCD...)]...) Suppress:(")")}) at loc 62(1,63)
Exception raised:Expected W:(ABCD...) (at char 62), (line:1, col:63)

---

我做错了什么？

您发布的代码的转储输出如下所示：

ADD(input1,input2) DEL(input3), SUB(input1,input2) INS(input3)

[[['ADD', ['input1', 'input2']], ['DEL', ['input3']]], [['SUB', ['input1', 'input2']], ['INS', ['input3']]]]
- line: [[['ADD', ['input1', 'input2']], ['DEL', ['input3']]], [['SUB', ['input1', 'input2']], ['INS', ['input3']]]]
  [0]:
    [['ADD', ['input1', 'input2']], ['DEL', ['input3']]]
    - instruction: ['DEL', ['input3']]
      - args: ['input3']
      - type: 'DEL'
  [1]:
    [['SUB', ['input1', 'input2']], ['INS', ['input3']]]
    - instruction: ['INS', ['input3']]
      - args: ['input3']
      - type: 'INS'

我们可以在dump（）输出中看到，所有指令都已解析，但在“指令”名称下只显示每组中的最后一条指令。这是因为，与Python dict一样，当多个值（在ZeroOrMore或OneOrMore中可能会得到）被分配给同一个键时，只保留最后一个值

有两种解决办法。一种方法是删除（“指令”）结果名称，以便只在每个子列表中获取已解析的指令：

[[['ADD', ['input1', 'input2']], ['DEL', ['input3']]], [['SUB', ['input1', 'input2']], ['INS', ['input3']]]]
- line: [[['ADD', ['input1', 'input2']], ['DEL', ['input3']]], [['SUB', ['input1', 'input2']], ['INS', ['input3']]]]
  [0]:
    [['ADD', ['input1', 'input2']], ['DEL', ['input3']]]
    [0]:
      ['ADD', ['input1', 'input2']]
      - args: ['input1', 'input2']
      - type: 'ADD'
    [1]:
      ['DEL', ['input3']]
      - args: ['input3']
      - type: 'DEL'
  [1]:
    [['SUB', ['input1', 'input2']], ['INS', ['input3']]]
    [0]:
      ['SUB', ['input1', 'input2']]
      - args: ['input1', 'input2']
      - type: 'SUB'
    [1]:
      ['INS', ['input3']]
      - args: ['input3']
      - type: 'INS'

在pyparsing中，有时应该为给定名称保存多个值。

setResultsName（）

方法有一个可选参数

listalMatches

，它启用此行为。当使用

setResultsName

的可调用快捷方式时，您不能传递

listAllMatches=True

——而是用“*”结束结果名称：

instruction = Group(instructionType 
                                + Literal("(").suppress() 
                                + arguments 
                                + Literal(")").suppress())("instruction*")

这将产生以下输出：

[[['ADD', ['input1', 'input2']], ['DEL', ['input3']]], [['SUB', ['input1', 'input2']], ['INS', ['input3']]]]
- line: [[['ADD', ['input1', 'input2']], ['DEL', ['input3']]], [['SUB', ['input1', 'input2']], ['INS', ['input3']]]]
  [0]:
    [['ADD', ['input1', 'input2']], ['DEL', ['input3']]]
    - instruction: [['ADD', ['input1', 'input2']], ['DEL', ['input3']]]
      [0]:
        ['ADD', ['input1', 'input2']]
        - args: ['input1', 'input2']
        - type: 'ADD'
      [1]:
        ['DEL', ['input3']]
        - args: ['input3']
        - type: 'DEL'
  [1]:
    [['SUB', ['input1', 'input2']], ['INS', ['input3']]]
    - instruction: [['SUB', ['input1', 'input2']], ['INS', ['input3']]]
      [0]:
        ['SUB', ['input1', 'input2']]
        - args: ['input1', 'input2']
        - type: 'SUB'
      [1]:
        ['INS', ['input3']]
        - args: ['input3']
        - type: 'INS'

---

您可以选择更适合的方法。

请使用

dump

@PaulMcG，而不是使用

asXML

打印结果。谢谢您的帮助！我已经在原来的问题中添加了转储文件。：）如果你做了

print（line.parseString（theInput.dump）

，你必须做

print（line.parseString（theInput.dump（））

@PaulMcG-Heh，woops。问题已更新。

instruction = Group(instructionType 
                                + Literal("(").suppress() 
                                + arguments 
                                + Literal(")").suppress())("instruction*")

[[['ADD', ['input1', 'input2']], ['DEL', ['input3']]], [['SUB', ['input1', 'input2']], ['INS', ['input3']]]]
- line: [[['ADD', ['input1', 'input2']], ['DEL', ['input3']]], [['SUB', ['input1', 'input2']], ['INS', ['input3']]]]
  [0]:
    [['ADD', ['input1', 'input2']], ['DEL', ['input3']]]
    - instruction: [['ADD', ['input1', 'input2']], ['DEL', ['input3']]]
      [0]:
        ['ADD', ['input1', 'input2']]
        - args: ['input1', 'input2']
        - type: 'ADD'
      [1]:
        ['DEL', ['input3']]
        - args: ['input3']
        - type: 'DEL'
  [1]:
    [['SUB', ['input1', 'input2']], ['INS', ['input3']]]
    - instruction: [['SUB', ['input1', 'input2']], ['INS', ['input3']]]
      [0]:
        ['SUB', ['input1', 'input2']]
        - args: ['input1', 'input2']
        - type: 'SUB'
      [1]:
        ['INS', ['input3']]
        - args: ['input3']
        - type: 'INS'