diff options
Diffstat (limited to 'pyparsing.py')
| -rw-r--r-- | pyparsing.py | 74 |
1 files changed, 71 insertions, 3 deletions
diff --git a/pyparsing.py b/pyparsing.py index 89c48d9..b688034 100644 --- a/pyparsing.py +++ b/pyparsing.py @@ -1,7 +1,7 @@ #-*- coding: utf-8 -*- # module pyparsing.py # -# Copyright (c) 2003-2018 Paul T. McGuire +# Copyright (c) 2003-2019 Paul T. McGuire # # Permission is hereby granted, free of charge, to any person obtaining # a copy of this software and associated documentation files (the @@ -94,7 +94,7 @@ classes inherit from. Use the docstrings for examples of how to: """ __version__ = "2.3.1" -__versionTime__ = "28 Dec 2018 20:52 UTC" +__versionTime__ = "05 Jan 2019 23:47 UTC" __author__ = "Paul McGuire <ptmcg@users.sourceforge.net>" import string @@ -311,7 +311,75 @@ class ParseException(ParseBaseException): column: 1 """ - pass + + @staticmethod + def explain(exc, depth=16): + """ + Method to take an exception and translate the Python internal traceback into a list + of the pyparsing expressions that caused the exception to be raised. + + Parameters: + + - exc - exception raised during parsing (need not be a ParseException, in support + of Python exceptions that might be raised in a parse action) + - depth (default=16) - number of levels back in the stack trace to list expression + and function names; if None, the full stack trace names will be listed; if 0, only + the failing input line, marker, and exception string will be shown + + Returns a multi-line string listing the ParserElements and/or function names in the + exception's stack trace. + + Note: the diagnostic output will include string representations of the expressions + that failed to parse. These representations will be more helpful if you use `setName` to + give identifiable names to your expressions. Otherwise they will use the default string + forms, which may be cryptic to read. + """ + import inspect + + if depth is None: + depth = sys.getrecursionlimit() + ret = [] + if isinstance(exc, ParseBaseException): + ret.append(exc.line) + ret.append(' ' * (exc.col - 1) + '^') + ret.append("{}: {}".format(type(exc).__name__, exc)) + + callers = inspect.getinnerframes(exc.__traceback__, context=depth) + seen = set() + + if depth > 0: + for i, ff in enumerate(callers[-depth:]): + frm = ff.frame + + f_self = frm.f_locals.get('self', None) + if isinstance(f_self, ParserElement): + if frm.f_code.co_name not in ('parseImpl', '_parseNoCache'): + continue + if f_self in seen: + continue + seen.add(f_self) + + self_type = type(f_self) + ret.append("{}.{} - {}".format(self_type.__module__, + self_type.__name__, + f_self)) + elif f_self is not None: + self_type = type(f_self) + ret.append("{}.{}".format(self_type.__module__, + self_type.__name__)) + else: + code = frm.f_code + if code.co_name in ('wrapper', '<module>'): + continue + + ret.append("{}".format(code.co_name)) + + depth -= 1 + if not depth: + break + + return '\n'.join(ret) + class ParseFatalException(ParseBaseException): """user-throwable exception thrown when inconsistent parse content |