Python解析器模块教程

Question

I am writing an application which reads an input file that currently has its own grammar, which is processed by lex/yacc.

I'm looking to modify this so as to make this input file a Python script instead, and was wondering if someone can point me to a beginner's guide to using the parser module in Python. I'm fairly new to Python itself, but have worked through a fair chunk of the online tutorial.

From what I have researched, I know there are options (such as pyparsing) which can allow me to keep the existing grammar and use Pyparsing as a replacement for lex/yacc. However, I am curious to learn the Python parser module in more detail and explore its feasibility.

Thanks.

Answer 1

You mean the parser module ? It's a parser for Python source code only, not a general purpose parser. You can't use it to parse anything else.

Answer 2

As Jochen said, the parser module is for parsing Python code. I think you're best off checking out Ned Batchelder's list of parsers . PyParsing does things pretty differently from Lex and Yacc, so I'm not sure why you think you could keep your existing grammar and lexer. A better bet might be David Beazley's PLY toolkit. It's solid and has excellent documentation.

Answer 3

I recommend that you check out https://github.com/erezsh/lark

It's great for newcomers to parsing: It can parse ALL context-free grammars, it automatically builds an AST (with line & column numbers), and it accepts the grammar in EBNF format, which is considered the standard and is very easy to write.