PLY (Python Lex-Yacc), an implementation of the lex and yacc parsing tools for Python.
PLY is an implementation of lex and yacc parsing tools for Python. In a nutshell, PLY is nothing more than a straightforward lex/yacc implementation. Here is a list of its essential features: It's implemented entirely in Python; It uses LR-parsing which is reasonably efficient and well suited for larger grammars; PLY provides most of the standard lex/yacc features including support for empty productions, precedence rules, error recovery, and support for ambiguous grammars; PLY is straightforward to use and provides very extensive error checking; PLY doesn't try to do anything more or less than provide the basic lex/yacc functionality. In other words, it's not a large parsing framework or a component of some larger system.