Question

我需要使用Python解析类似下面的文本文件，构建数据的分层对象结构然后进行处理。这与我们可以使用xml.etree.ElementTree和其他XML解析器非常相似。

然而，这些文件的语法不是XML，我想知道实现这样一个解析器的最佳方法是什么：如果尝试子类化一个XML解析器（哪一个？）并自定义其标记识别行为，写一个自定义解析器等。

{NETLIST topblock
{VERSION 2 0 0}

{CELL topblock
    {PORT gearshift_h vpsf vphreg pwron_h vinp vref_out vcntrl_out gd meas_vref 
      vb vout meas_vcntrl reset_h vinm }
    {INST XI21/Mdummy1=pch_18_mac {TYPE MOS} {PROP n="sctg_inv1x/pch_18_mac" Length=0.152 NFIN=8 }
    {PIN vpsf=SRC gs_h=DRN vpsf=GATE vpsf=BULK }}
    {INST XI21/Mdummy2=nch_18_mac {TYPE MOS} {PROP n="sctg_inv1x/nch_18_mac" Length=0.152 NFIN=5 }
    {PIN gs_h=SRC gd=DRN gd=GATE gd=BULK }}
    {INST XI20/Mdummy1=pch_18_mac {TYPE MOS} {PROP n="sctg_inv1x/pch_18_mac" Length=0.152 NFIN=8 }
    {PIN vpsf=SRC gs_hn=DRN vpsf=GATE vpsf=BULK }}
    {INST XI20/Mdummy2=nch_18_mac {TYPE MOS} {PROP n="sctg_inv1x/nch_18_mac" Length=0.152 NFIN=5 }
    {PIN gs_hn=SRC gd=DRN gd=GATE gd=BULK }}
    {INST XI19/Mdummy1=pch_18_mac {TYPE MOS} {PROP n="sctg_inv1x/pch_18_mac" Length=0.152 NFIN=8 }
    {PIN vpsf=SRC net514=DRN vpsf=GATE vpsf=BULK }}
    {INST XI19/Mdummy2=nch_18_mac {TYPE MOS} {PROP n="sctg_inv1x/nch_18_mac" Length=0.152 NFIN=5 }
    {PIN net514=SRC gd=DRN gd=GATE gd=BULK }}
    {INST XI21/MN0=nch_18_mac {TYPE MOS} {PROP n="sctg_inv1x/nch_18_mac" Length=0.152 NFIN=5 }
    {PIN gd=SRC gs_h=DRN gs_hn=GATE gd=BULK }}
    {INST XI21/MP0=pch_18_mac {TYPE MOS} {PROP n="sctg_inv1x/pch_18_mac" Length=0.152 NFIN=8 }
    {PIN vpsf=SRC gs_h=DRN gs_hn=GATE vpsf=BULK }}
    {INST XI20/MN0=nch_18_mac {TYPE MOS} {PROP n="sctg_inv1x/nch_18_mac" Length=0.152 NFIN=5 }
...
}
}

Answer 1

首先，您应该检查是否已有可用于您的文件格式的解析器。显然有：Python-based Verilog Parser (currently Netlist only)

如果找不到合适的东西，可以使用一个过多的可用库构建解析器来构建解析器，例如pyparsing。子类化XML解析器似乎不是一个好主意。

Answer 2

其他人在评论中说：使用现有的解析器。如果不存在，请自行滚动，但使用解析器库。这里例如与Parcon：

from pprint import pprint
from parcon import (Forward, SignificantLiteral, Word, alphanum_chars, Exact,
                    ZeroOrMore, CharNotIn, concat, OneOrMore)

block = Forward()
hyphen = SignificantLiteral('"')
word = Word(alphanum_chars + '/_.)')
value = word | Exact(hyphen + ZeroOrMore(CharNotIn('"')) + hyphen)[concat]
pair = word + '=' + value
flag = word
attribute = pair | flag | block
head = word
body = ZeroOrMore(attribute)
block << '{' + head + body  + '}'
blocks = OneOrMore(block)

with open('<your file name>.txt') as infile:
    pprint(blocks.parse_string(infile.read()))

结果：

[('NETLIST',
  ['topblock',
   ('VERSION', ['2', '0', '0']),
   ('CELL',
    ['topblock',
     ('PORT',
      ['gearshift_h',
       'vpsf',
       'vphreg',
       'pwron_h',
       'vinp',
       'vref_out',
       'vcntrl_out',
       'gd',
       'meas_vref',
       'vb',
       'vout',
       'meas_vcntrl',
       'reset_h',
       'vinm']),
     ('INST',
      [('XI21/Mdummy1', 'pch_18_mac'),
       ('TYPE', ['MOS']),
       ('PROP',
        [('n', '"sctg_inv1x/pch_18_mac"'),
         ('Length', '0.152'),
         ('NFIN', '8')]),
       ('PIN',
        [('vpsf', 'SRC'),
         ('gs_h', 'DRN'),
         ('vpsf', 'GATE'),
         ('vpsf', 'BULK')])]),
     ('INST',
        ...

在python中解析结构化文本文件

2 个答案: