""" Verbose and colourful traceback formatting. **ColorTB** I've always found it a bit hard to visually parse tracebacks in Python. The ColorTB class is a solution to that problem. It colors the different parts of a traceback in a manner similar to what you would expect from a syntax-highlighting text editor. Installation instructions for ColorTB:: import sys,ultratb sys.excepthook = ultratb.ColorTB() **VerboseTB** I've also included a port of Ka-Ping Yee's "cgitb.py" that produces all kinds of useful info when a traceback occurs. Ping originally had it spit out HTML and intended it for CGI programmers, but why should they have all the fun? I altered it to spit out colored text to the terminal. It's a bit overwhelming, but kind of neat, and maybe useful for long-running programs that you believe are bug-free. If a crash *does* occur in that type of program you want details. Give it a shot--you'll love it or you'll hate it. .. note:: The Verbose mode prints the variables currently visible where the exception happened (shortening their strings if too long). This can potentially be very slow, if you happen to have a huge data structure whose string representation is complex to compute. Your computer may appear to freeze for a while with cpu usage at 100%. If this occurs, you can cancel the traceback with Ctrl-C (maybe hitting it more than once). If you encounter this kind of situation often, you may want to use the Verbose_novars mode instead of the regular Verbose, which avoids formatting variables (but otherwise includes the information and context given by Verbose). .. note:: The verbose mode print all variables in the stack, which means it can potentially leak sensitive information like access keys, or unencrypted password. Installation instructions for VerboseTB:: import sys,ultratb sys.excepthook = ultratb.VerboseTB() Note: Much of the code in this module was lifted verbatim from the standard library module 'traceback.py' and Ka-Ping Yee's 'cgitb.py'. Inheritance diagram: .. inheritance-diagram:: IPython.core.ultratb :parts: 3 """ # ***************************************************************************** # Copyright (C) 2001 Nathaniel Gray # Copyright (C) 2001-2004 Fernando Perez # # Distributed under the terms of the BSD License. The full license is in # the file COPYING, distributed as part of this software. # ***************************************************************************** import functools import inspect import linecache import sys import time import traceback import types import warnings from collections.abc import Sequence from types import TracebackType from typing import Any, Callable, List, Optional, Tuple import stack_data from pygments.formatters.terminal256 import Terminal256Formatter from pygments.token import Token from IPython import get_ipython from IPython.utils import path as util_path from IPython.utils import py3compat from IPython.utils.PyColorize import Parser, Theme, TokenStream, theme_table from IPython.utils.terminal import get_terminal_size from .display_trap import DisplayTrap from .doctb import DocTB from .tbtools import ( FrameInfo, TBTools, _format_traceback_lines, _safe_string, _simple_format_traceback_lines, _tokens_filename, eqrepr, get_line_number_of_frame, nullrepr, text_repr, ) # Globals # amount of space to put line numbers before verbose tracebacks INDENT_SIZE = 8 # When files are too long do not use stackdata to get frames. # it is too long. FAST_THRESHOLD = 10_000 # --------------------------------------------------------------------------- class ListTB(TBTools): """Print traceback information from a traceback list, with optional color. Calling requires 3 arguments: (etype, evalue, elist) as would be obtained by:: etype, evalue, tb = sys.exc_info() if tb: elist = traceback.extract_tb(tb) else: elist = None It can thus be used by programs which need to process the traceback before printing (such as console replacements based on the code module from the standard library). Because they are meant to be called without a full traceback (only a list), instances of this class can't call the interactive pdb debugger.""" def __call__( self, etype: type[BaseException], evalue: BaseException | None, etb: TracebackType | None, ) -> None: self.ostream.flush() self.ostream.write(self.text(etype, evalue, etb)) self.ostream.write("\n") def _extract_tb(self, tb: TracebackType | None) -> traceback.StackSummary | None: if tb: return traceback.extract_tb(tb) else: return None def structured_traceback( self, etype: type, evalue: Optional[BaseException], etb: Optional[TracebackType] = None, tb_offset: Optional[int] = None, context: int = 5, ) -> list[str]: """Return a color formatted string with the traceback info. Parameters ---------- etype : exception type Type of the exception raised. evalue : object Data stored in the exception etb : list | TracebackType | None If list: List of frames, see class docstring for details. If Traceback: Traceback of the exception. tb_offset : int, optional Number of frames in the traceback to skip. If not given, the instance evalue is used (set in constructor). context : int, optional Number of lines of context information to print. Returns ------- String with formatted exception. """ # This is a workaround to get chained_exc_ids in recursive calls # etb should not be a tuple if structured_traceback is not recursive if isinstance(etb, tuple): etb, chained_exc_ids = etb else: chained_exc_ids = set() elist: list[Any] if isinstance(etb, list): elist = etb elif etb is not None: elist = self._extract_tb(etb) # type: ignore[assignment] else: elist = [] tb_offset = self.tb_offset if tb_offset is None else tb_offset assert isinstance(tb_offset, int) out_list: list[str] = [] if elist: if tb_offset and len(elist) > tb_offset: elist = elist[tb_offset:] out_list.append( theme_table[self._theme_name].format( [ (Token, "Traceback"), (Token, " "), (Token.NormalEm, "(most recent call last)"), (Token, ":"), (Token, "\n"), ] ), ) out_list.extend(self._format_list(elist)) # The exception info should be a single entry in the list. lines = "".join(self._format_exception_only(etype, evalue)) out_list.append(lines) # Find chained exceptions if we have a traceback (not for exception-only mode) if etb is not None: exception = self.get_parts_of_chained_exception(evalue) if exception and (id(exception[1]) not in chained_exc_ids): chained_exception_message: list[str] = ( self.prepare_chained_exception_message(evalue.__cause__)[0] if evalue is not None else [""] ) etype, evalue, etb = exception # Trace exception to avoid infinite 'cause' loop chained_exc_ids.add(id(exception[1])) chained_exceptions_tb_offset = 0 ol1 = self.structured_traceback( etype, evalue, (etb, chained_exc_ids), # type: ignore[arg-type] chained_exceptions_tb_offset, context, ) ol2 = chained_exception_message out_list = ol1 + ol2 + out_list return out_list def _format_list(self, extracted_list: list[Any]) -> list[str]: """Format a list of traceback entry tuples for printing. Given a list of tuples as returned by extract_tb() or extract_stack(), return a list of strings ready for printing. Each string in the resulting list corresponds to the item with the same index in the argument list. Each string ends in a newline; the strings may contain internal newlines as well, for those items whose source text line is not None. Lifted almost verbatim from traceback.py """ output_list = [] for ind, (filename, lineno, name, line) in enumerate(extracted_list): # Will emphasize the last entry em = True if ind == len(extracted_list) - 1 else False item = theme_table[self._theme_name].format( [(Token.NormalEm if em else Token.Normal, " ")] + _tokens_filename(em, filename, lineno=lineno) ) # This seem to be only in xmode plain (%run sinpleer), investigate why not share with verbose. # look at _tokens_filename in forma_record. if name != "": item += theme_table[self._theme_name].format( [ (Token.NormalEm if em else Token.Normal, " in "), (Token.TB.NameEm if em else Token.TB.Name, name), ] ) item += theme_table[self._theme_name].format( [(Token.NormalEm if em else Token, "\n")] ) if line: item += theme_table[self._theme_name].format( [ (Token.Line if em else Token, " "), (Token.Line if em else Token, line.strip()), (Token, "\n"), ] ) output_list.append(item) return output_list def _format_exception_only( self, etype: type[BaseException], value: BaseException | None ) -> list[str]: """Format the exception part of a traceback. The arguments are the exception type and value such as given by sys.exc_info()[:2]. The return value is a list of strings, each ending in a newline. Normally, the list contains a single string; however, for SyntaxError exceptions, it contains several lines that (when printed) display detailed information about where the syntax error occurred. The message indicating which exception occurred is the always last string in the list. Also lifted nearly verbatim from traceback.py """ have_filedata = False output_list = [] stype_tokens = [(Token.ExcName, etype.__name__)] stype: str = theme_table[self._theme_name].format(stype_tokens) if value is None: # Not sure if this can still happen in Python 2.6 and above output_list.append(stype + "\n") else: if issubclass(etype, SyntaxError): assert hasattr(value, "filename") assert hasattr(value, "lineno") assert hasattr(value, "text") assert hasattr(value, "offset") assert hasattr(value, "msg") have_filedata = True if not value.filename: value.filename = "" if value.lineno: lineno = value.lineno textline = linecache.getline(value.filename, value.lineno) else: lineno = "unknown" textline = "" output_list.append( theme_table[self._theme_name].format( [(Token, " ")] + _tokens_filename( True, value.filename, lineno=(None if lineno == "unknown" else lineno), ) + [(Token, "\n")] ) ) if textline == "": # sep 2025: # textline = py3compat.cast_unicode(value.text, "utf-8") if value.text is None: textline = "" else: assert isinstance(value.text, str) textline = value.text if textline is not None: i = 0 while i < len(textline) and textline[i].isspace(): i += 1 output_list.append( theme_table[self._theme_name].format( [ (Token.Line, " "), (Token.Line, textline.strip()), (Token, "\n"), ] ) ) if value.offset is not None: s = " " for c in textline[i : value.offset - 1]: if c.isspace(): s += c else: s += " " output_list.append( theme_table[self._theme_name].format( [(Token.Caret, s + "^"), (Token, "\n")] ) ) s = value.msg else: s = self._some_str(value) if s: output_list.append( theme_table[self._theme_name].format( stype_tokens + [ (Token.ExcName, ":"), (Token, " "), (Token, s), (Token, "\n"), ] ) ) else: output_list.append("%s\n" % stype) # PEP-678 notes output_list.extend(f"{x}\n" for x in getattr(value, "__notes__", [])) # sync with user hooks if have_filedata: ipinst = get_ipython() if ipinst is not None: assert value is not None assert hasattr(value, "lineno") assert hasattr(value, "filename") ipinst.hooks.synchronize_with_editor(value.filename, value.lineno, 0) return output_list def get_exception_only(self, etype, value): """Only print the exception type and message, without a traceback. Parameters ---------- etype : exception type value : exception value """ return ListTB.structured_traceback(self, etype, value) def show_exception_only( self, etype: BaseException | None, evalue: TracebackType | None ) -> None: """Only print the exception type and message, without a traceback. Parameters ---------- etype : exception type evalue : exception value """ # This method needs to use __call__ from *this* class, not the one from # a subclass whose signature or behavior may be different ostream = self.ostream ostream.flush() ostream.write("\n".join(self.get_exception_only(etype, evalue))) ostream.flush() def _some_str(self, value: Any) -> str: # Lifted from traceback.py try: return str(value) except: return "" % type(value).__name__ _sentinel = object() _default = "default" # ---------------------------------------------------------------------------- class VerboseTB(TBTools): """A port of Ka-Ping Yee's cgitb.py module that outputs color text instead of HTML. Requires inspect and pydoc. Crazy, man. Modified version which optionally strips the topmost entries from the traceback, to be used with alternate interpreters (because their own code would appear in the traceback).""" tb_highlight = "bg:ansiyellow" tb_highlight_style = "default" _mode: str def __init__( self, # TODO: no default ? theme_name: str = _default, call_pdb: bool = False, ostream: Any = None, tb_offset: int = 0, long_header: bool = False, include_vars: bool = True, check_cache: Callable[[], None] | None = None, debugger_cls: type | None = None, *, color_scheme: Any = _sentinel, ): """Specify traceback offset, headers and color scheme. Define how many frames to drop from the tracebacks. Calling it with tb_offset=1 allows use of this handler in interpreters which will have their own code at the top of the traceback (VerboseTB will first remove that frame before printing the traceback info).""" if color_scheme is not _sentinel: assert isinstance(color_scheme, str) theme_name = color_scheme.lower() warnings.warn( "color_scheme is deprecated as of IPython 9.0 and replaced by " "theme_name (which should be lowercase). As you passed a " "color_scheme value I will try to see if I have corresponding " "theme.", stacklevel=2, category=DeprecationWarning, ) if theme_name != _default: warnings.warn( "You passed both `theme_name` and `color_scheme` " "(deprecated) to VerboseTB constructor. `theme_name` will " "be ignored for the time being.", stacklevel=2, category=DeprecationWarning, ) if theme_name == _default: theme_name = "linux" assert isinstance(theme_name, str) super().__init__( theme_name=theme_name, call_pdb=call_pdb, ostream=ostream, debugger_cls=debugger_cls, ) self.tb_offset = tb_offset self.long_header = long_header self.include_vars = include_vars # By default we use linecache.checkcache, but the user can provide a # different check_cache implementation. This was formerly used by the # IPython kernel for interactive code, but is no longer necessary. if check_cache is None: check_cache = linecache.checkcache self.check_cache = check_cache self.skip_hidden = True def format_record(self, frame_info: FrameInfo) -> str: """Format a single stack frame""" assert isinstance(frame_info, FrameInfo) if isinstance(frame_info._sd, stack_data.RepeatedFrames): return theme_table[self._theme_name].format( [ (Token, " "), ( Token.ExcName, "[... skipping similar frames: %s]" % frame_info.description, ), (Token, "\n"), ] ) indent: str = " " * INDENT_SIZE assert isinstance(frame_info.lineno, int) args, varargs, varkw, locals_ = inspect.getargvalues(frame_info.frame) if frame_info.executing is not None: func = frame_info.executing.code_qualname() else: func = "?" if func == "": call = "" else: # Decide whether to include variable details or not var_repr = eqrepr if self.include_vars else nullrepr try: scope = inspect.formatargvalues( args, varargs, varkw, locals_, formatvalue=var_repr ) assert isinstance(scope, str) call = theme_table[self._theme_name].format( [(Token, "in "), (Token.VName, func), (Token.ValEm, scope)] ) except KeyError: # This happens in situations like errors inside generator # expressions, where local variables are listed in the # line, but can't be extracted from the frame. I'm not # 100% sure this isn't actually a bug in inspect itself, # but since there's no info for us to compute with, the # best we can do is report the failure and move on. Here # we must *not* call any traceback construction again, # because that would mess up use of %debug later on. So we # simply report the failure and move on. The only # limitation will be that this frame won't have locals # listed in the call signature. Quite subtle problem... # I can't think of a good way to validate this in a unit # test, but running a script consisting of: # dict( (k,v.strip()) for (k,v) in range(10) ) # will illustrate the error, if this exception catch is # disabled. call = theme_table[self._theme_name].format( [ (Token, "in "), (Token.VName, func), (Token.ValEm, "(***failed resolving arguments***)"), ] ) lvals_toks: list[TokenStream] = [] if self.include_vars: try: # we likely want to fix stackdata at some point, but # still need a workaround. fibp = frame_info.variables_in_executing_piece for var in fibp: lvals_toks.append( [ (Token, var.name), (Token, " "), (Token.ValEm, "= "), (Token.ValEm, repr(var.value)), ] ) except Exception: lvals_toks.append( [ ( Token, "Exception trying to inspect frame. No more locals available.", ), ] ) if frame_info._sd is None: # fast fallback if file is too long assert frame_info.filename is not None level_tokens = [ (Token.FilenameEm, util_path.compress_user(frame_info.filename)), (Token, " "), (Token, call), (Token, "\n"), ] _line_format = Parser(theme_name=self._theme_name).format2 assert isinstance(frame_info.code, types.CodeType) first_line: int = frame_info.code.co_firstlineno current_line: int = frame_info.lineno raw_lines: list[str] = frame_info.raw_lines index: int = current_line - first_line assert frame_info.context is not None if index >= frame_info.context: start = max(index - frame_info.context, 0) stop = index + frame_info.context index = frame_info.context else: start = 0 stop = index + frame_info.context raw_lines = raw_lines[start:stop] # Jan 2025: may need _line_format(py3ompat.cast_unicode(s)) raw_color_err = [(s, _line_format(s, "str")) for s in raw_lines] tb_tokens = _simple_format_traceback_lines( current_line, index, raw_color_err, lvals_toks, theme=theme_table[self._theme_name], ) _tb_lines: str = theme_table[self._theme_name].format(tb_tokens) return theme_table[self._theme_name].format(level_tokens + tb_tokens) else: result = theme_table[self._theme_name].format( _tokens_filename(True, frame_info.filename, lineno=frame_info.lineno) ) result += ", " if call else "" result += f"{call}\n" result += theme_table[self._theme_name].format( _format_traceback_lines( frame_info.lines, theme_table[self._theme_name], self.has_colors, lvals_toks, ) ) return result def prepare_header(self, etype: str, long_version: bool = False) -> str: width = min(75, get_terminal_size()[0]) if long_version: # Header with the exception type, python version, and date pyver = "Python " + sys.version.split()[0] + ": " + sys.executable date = time.ctime(time.time()) theme = theme_table[self._theme_name] head = theme.format( [ (Token.Topline, theme.symbols["top_line"] * width), (Token, "\n"), (Token.ExcName, etype), (Token, " " * (width - len(etype) - len(pyver))), (Token, pyver), (Token, "\n"), (Token, date.rjust(width)), ] ) head += ( "\nA problem occurred executing Python code. Here is the sequence of function" "\ncalls leading up to the error, with the most recent (innermost) call last." ) else: # Simplified header head = theme_table[self._theme_name].format( [ (Token.ExcName, etype), ( Token, "Traceback (most recent call last)".rjust(width - len(etype)), ), ] ) return head def format_exception(self, etype, evalue): # Get (safely) a string form of the exception info try: etype_str, evalue_str = map(str, (etype, evalue)) except: # User exception is improperly defined. etype, evalue = str, sys.exc_info()[:2] etype_str, evalue_str = map(str, (etype, evalue)) # PEP-678 notes notes = getattr(evalue, "__notes__", []) if not isinstance(notes, Sequence) or isinstance(notes, (str, bytes)): notes = [_safe_string(notes, "__notes__", func=repr)] for note in notes: assert isinstance(note, str) str_notes: Sequence[str] = notes # ... and format it return [ theme_table[self._theme_name].format( [(Token.ExcName, etype_str), (Token, ": "), (Token, evalue_str)] ), *( theme_table[self._theme_name].format([(Token, note)]) for note in str_notes ), ] def format_exception_as_a_whole( self, etype: type, evalue: Optional[BaseException], etb: Optional[TracebackType], context: int, tb_offset: Optional[int], ) -> list[list[str]]: """Formats the header, traceback and exception message for a single exception. This may be called multiple times by Python 3 exception chaining (PEP 3134). """ # some locals orig_etype = etype try: etype = etype.__name__ # type: ignore[assignment] except AttributeError: pass tb_offset = self.tb_offset if tb_offset is None else tb_offset assert isinstance(tb_offset, int) head = self.prepare_header(str(etype), self.long_header) records = self.get_records(etb, context, tb_offset) if etb else [] frames = [] skipped = 0 lastrecord = len(records) - 1 for i, record in enumerate(records): if ( not isinstance(record._sd, stack_data.RepeatedFrames) and self.skip_hidden ): if ( record.frame.f_locals.get("__tracebackhide__", 0) and i != lastrecord ): skipped += 1 continue if skipped: frames.append( theme_table[self._theme_name].format( [ (Token, " "), (Token.ExcName, "[... skipping hidden %s frame]" % skipped), (Token, "\n"), ] ) ) skipped = 0 frames.append(self.format_record(record)) if skipped: frames.append( theme_table[self._theme_name].format( [ (Token, " "), (Token.ExcName, "[... skipping hidden %s frame]" % skipped), (Token, "\n"), ] ) ) formatted_exception = self.format_exception(etype, evalue) if records: frame_info = records[-1] ipinst = get_ipython() if ipinst is not None: ipinst.hooks.synchronize_with_editor( frame_info.filename, frame_info.lineno, 0 ) return [[head] + frames + formatted_exception] def get_records(self, etb: TracebackType, context: int, tb_offset: int) -> Any: assert etb is not None context = context - 1 after = context // 2 before = context - after if self.has_colors: base_style = theme_table[self._theme_name].as_pygments_style() style = stack_data.style_with_executing_node(base_style, self.tb_highlight) formatter = Terminal256Formatter(style=style) else: formatter = None options = stack_data.Options( before=before, after=after, pygments_formatter=formatter, ) # Let's estimate the amount of code we will have to parse/highlight. cf: Optional[TracebackType] = etb max_len = 0 tbs = [] while cf is not None: try: mod = inspect.getmodule(cf.tb_frame) if mod is not None: mod_name = mod.__name__ root_name, *_ = mod_name.split(".") if root_name == "IPython": cf = cf.tb_next continue max_len = get_line_number_of_frame(cf.tb_frame) except OSError: max_len = 0 max_len = max(max_len, max_len) tbs.append(cf) cf = getattr(cf, "tb_next", None) if max_len > FAST_THRESHOLD: FIs: list[FrameInfo] = [] for tb in tbs: frame = tb.tb_frame # type: ignore[union-attr] lineno = frame.f_lineno code = frame.f_code filename = code.co_filename # TODO: Here we need to use before/after/ FIs.append( FrameInfo( "Raw frame", filename, lineno, frame, code, context=context ) ) return FIs res = list(stack_data.FrameInfo.stack_data(etb, options=options))[tb_offset:] res2 = [FrameInfo._from_stack_data_FrameInfo(r) for r in res] return res2 def structured_traceback( self, etype: type, evalue: Optional[BaseException], etb: Optional[TracebackType] = None, tb_offset: Optional[int] = None, context: int = 5, ) -> list[str]: """Return a nice text document describing the traceback.""" formatted_exceptions: list[list[str]] = self.format_exception_as_a_whole( etype, evalue, etb, context, tb_offset ) termsize = min(75, get_terminal_size()[0]) theme = theme_table[self._theme_name] head: str = theme.format( [ ( Token.Topline, theme.symbols["top_line"] * termsize, ), ] ) structured_traceback_parts: list[str] = [head] chained_exceptions_tb_offset = 0 lines_of_context = 3 exception = self.get_parts_of_chained_exception(evalue) if exception: assert evalue is not None formatted_exceptions += self.prepare_chained_exception_message( evalue.__cause__ ) etype, evalue, etb = exception else: evalue = None chained_exc_ids = set() while evalue: formatted_exceptions += self.format_exception_as_a_whole( etype, evalue, etb, lines_of_context, chained_exceptions_tb_offset ) exception = self.get_parts_of_chained_exception(evalue) if exception and id(exception[1]) not in chained_exc_ids: chained_exc_ids.add( id(exception[1]) ) # trace exception to avoid infinite 'cause' loop formatted_exceptions += self.prepare_chained_exception_message( evalue.__cause__ ) etype, evalue, etb = exception else: evalue = None # we want to see exceptions in a reversed order: # the first exception should be on top for fx in reversed(formatted_exceptions): structured_traceback_parts += fx return structured_traceback_parts def debugger(self, force: bool = False) -> None: """Call up the pdb debugger if desired, always clean up the tb reference. Keywords: - force(False): by default, this routine checks the instance call_pdb flag and does not actually invoke the debugger if the flag is false. The 'force' option forces the debugger to activate even if the flag is false. If the call_pdb flag is set, the pdb interactive debugger is invoked. In all cases, the self.tb reference to the current traceback is deleted to prevent lingering references which hamper memory management. Note that each call to pdb() does an 'import readline', so if your app requires a special setup for the readline completers, you'll have to fix that by hand after invoking the exception handler.""" if force or self.call_pdb: if self.pdb is None: self.pdb = self.debugger_cls() # the system displayhook may have changed, restore the original # for pdb display_trap = DisplayTrap(hook=sys.__displayhook__) with display_trap: self.pdb.reset() # Find the right frame so we don't pop up inside ipython itself if hasattr(self, "tb") and self.tb is not None: # type: ignore[has-type] etb = self.tb # type: ignore[has-type] else: etb = self.tb = sys.last_traceback while self.tb is not None and self.tb.tb_next is not None: assert self.tb.tb_next is not None self.tb = self.tb.tb_next if etb and etb.tb_next: etb = etb.tb_next self.pdb.botframe = etb.tb_frame # last_value should be deprecated, but last-exc sometimme not set # please check why later and remove the getattr. exc = ( sys.last_value if sys.version_info < (3, 12) else getattr(sys, "last_exc", sys.last_value) ) # type: ignore[attr-defined] if exc: self.pdb.interaction(None, exc) else: self.pdb.interaction(None, etb) if hasattr(self, "tb"): del self.tb def handler(self, info=None): (etype, evalue, etb) = info or sys.exc_info() self.tb = etb ostream = self.ostream ostream.flush() ostream.write(self.text(etype, evalue, etb)) # type:ignore[arg-type] ostream.write("\n") ostream.flush() # Changed so an instance can just be called as VerboseTB_inst() and print # out the right info on its own. def __call__(self, etype=None, evalue=None, etb=None): """This hook can replace sys.excepthook (for Python 2.1 or higher).""" if etb is None: self.handler() else: self.handler((etype, evalue, etb)) try: self.debugger() except KeyboardInterrupt: print("\nKeyboardInterrupt") # ---------------------------------------------------------------------------- class FormattedTB(VerboseTB, ListTB): """Subclass ListTB but allow calling with a traceback. It can thus be used as a sys.excepthook for Python > 2.1. Also adds 'Context' and 'Verbose' modes, not available in ListTB. Allows a tb_offset to be specified. This is useful for situations where one needs to remove a number of topmost frames from the traceback (such as occurs with python programs that themselves execute other python code, like Python shells).""" mode: str def __init__( self, mode="Plain", # TODO: no default theme_name="linux", call_pdb=False, ostream=None, tb_offset=0, long_header=False, include_vars=False, check_cache=None, debugger_cls=None, ): # NEVER change the order of this list. Put new modes at the end: self.valid_modes = ["Plain", "Context", "Verbose", "Minimal", "Docs"] self.verbose_modes = self.valid_modes[1:3] VerboseTB.__init__( self, theme_name=theme_name, call_pdb=call_pdb, ostream=ostream, tb_offset=tb_offset, long_header=long_header, include_vars=include_vars, check_cache=check_cache, debugger_cls=debugger_cls, ) # Different types of tracebacks are joined with different separators to # form a single string. They are taken from this dict self._join_chars = dict( Plain="", Context="\n", Verbose="\n", Minimal="", Docs="" ) # set_mode also sets the tb_join_char attribute self.set_mode(mode) def structured_traceback( self, etype: type, evalue: BaseException | None, etb: TracebackType | None = None, tb_offset: int | None = None, context: int = 5, ) -> list[str]: tb_offset = self.tb_offset if tb_offset is None else tb_offset mode = self.mode if mode in self.verbose_modes: # Verbose modes need a full traceback return VerboseTB.structured_traceback( self, etype, evalue, etb, tb_offset, context ) elif mode == "Docs": # return DocTB return DocTB( theme_name=self._theme_name, call_pdb=self.call_pdb, ostream=self.ostream, tb_offset=tb_offset, long_header=self.long_header, include_vars=self.include_vars, check_cache=self.check_cache, debugger_cls=self.debugger_cls, ).structured_traceback( etype, evalue, etb, tb_offset, 1 ) # type: ignore[arg-type] elif mode == "Minimal": return ListTB.get_exception_only(self, etype, evalue) else: # We must check the source cache because otherwise we can print # out-of-date source code. self.check_cache() # Now we can extract and format the exception return ListTB.structured_traceback( self, etype, evalue, etb, tb_offset, context ) def stb2text(self, stb: list[str]) -> str: """Convert a structured traceback (a list) to a string.""" return self.tb_join_char.join(stb) def set_mode(self, mode: Optional[str] = None) -> None: """Switch to the desired mode. If mode is not specified, cycles through the available modes.""" if not mode: new_idx = (self.valid_modes.index(self.mode) + 1) % len(self.valid_modes) self.mode = self.valid_modes[new_idx] elif mode not in self.valid_modes: raise ValueError( "Unrecognized mode in FormattedTB: <" + mode + ">\n" "Valid modes: " + str(self.valid_modes) ) else: assert isinstance(mode, str) self.mode = mode # include variable details only in 'Verbose' mode self.include_vars = self.mode == self.valid_modes[2] # Set the join character for generating text tracebacks self.tb_join_char = self._join_chars[self.mode] # some convenient shortcuts def plain(self) -> None: self.set_mode(self.valid_modes[0]) def context(self) -> None: self.set_mode(self.valid_modes[1]) def verbose(self) -> None: self.set_mode(self.valid_modes[2]) def minimal(self) -> None: self.set_mode(self.valid_modes[3]) # ---------------------------------------------------------------------------- class AutoFormattedTB(FormattedTB): """A traceback printer which can be called on the fly. It will find out about exceptions by itself. A brief example:: AutoTB = AutoFormattedTB(mode = 'Verbose', theme_name='linux') try: ... except: AutoTB() # or AutoTB(out=logfile) where logfile is an open file object """ def __call__( self, etype: type | None = None, evalue: BaseException | None = None, etb: TracebackType | None = None, out: Any = None, tb_offset: int | None = None, ) -> None: """Print out a formatted exception traceback. Optional arguments: - out: an open file-like object to direct output to. - tb_offset: the number of frames to skip over in the stack, on a per-call basis (this overrides temporarily the instance's tb_offset given at initialization time.""" if out is None: out = self.ostream out.flush() out.write(self.text(etype, evalue, etb, tb_offset)) # type:ignore[arg-type] out.write("\n") out.flush() # FIXME: we should remove the auto pdb behavior from here and leave # that to the clients. try: self.debugger() except KeyboardInterrupt: print("\nKeyboardInterrupt") def structured_traceback( self, etype: type, evalue: Optional[BaseException], etb: Optional[TracebackType] = None, tb_offset: Optional[int] = None, context: int = 5, ) -> list[str]: # tb: TracebackType or tupleof tb types ? if etype is None: etype, evalue, etb = sys.exc_info() if isinstance(etb, tuple): # tb is a tuple if this is a chained exception. self.tb = etb[0] else: self.tb = etb return FormattedTB.structured_traceback( self, etype, evalue, etb, tb_offset, context ) # --------------------------------------------------------------------------- # A simple class to preserve Nathan's original functionality. class ColorTB(FormattedTB): """Deprecated since IPython 9.0.""" def __init__(self, *args, **kwargs): warnings.warn( "Deprecated since IPython 9.0 use FormattedTB directly ColorTB is just an alias", DeprecationWarning, stacklevel=2, ) super().__init__(*args, **kwargs) class SyntaxTB(ListTB): """Extension which holds some state: the last exception value""" last_syntax_error: BaseException | None def __init__(self, *, theme_name): super().__init__(theme_name=theme_name) self.last_syntax_error = None def __call__(self, etype, value, elist): self.last_syntax_error = value super().__call__(etype, value, elist) def structured_traceback( self, etype: type, evalue: BaseException | None, etb: TracebackType | None = None, tb_offset: int | None = None, context: int = 5, ) -> list[str]: value = evalue # If the source file has been edited, the line in the syntax error can # be wrong (retrieved from an outdated cache). This replaces it with # the current value. if ( isinstance(value, SyntaxError) and isinstance(value.filename, str) and isinstance(value.lineno, int) ): linecache.checkcache(value.filename) newtext = linecache.getline(value.filename, value.lineno) if newtext: value.text = newtext self.last_syntax_error = value return super(SyntaxTB, self).structured_traceback( etype, value, etb, tb_offset=tb_offset, context=context ) def clear_err_state(self) -> Any | None: """Return the current error state and clear it""" e = self.last_syntax_error self.last_syntax_error = None return e def stb2text(self, stb: list[str]) -> str: """Convert a structured traceback (a list) to a string.""" return "".join(stb)