"""

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 <[email protected]>

# Copyright (C) 2001-2004 Fernando Perez <[email protected]>

#

# 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, List, Optional, Tuple

from collections.abc import Callable

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 != "<module>":

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 = "<string>"

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 "<unprintable %s object>" % 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)

func: str

if frame_info.executing is not None:

func = frame_info.executing.code_qualname()

elif frame_info.code is not None:

func = (

getattr(frame_info.code, "co_qualname", None) or frame_info.code.co_name

)

else:

func = "?"

if func == "<module>":

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 = (

_tokens_filename(True, frame_info.filename, lineno=frame_info.lineno)

+ [

(Token, ", " if call else ""),

(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 = []

for s in raw_lines:

formatted, is_error = _line_format(s, "str")

assert formatted is not None, "format2 should return str when out='str'"

raw_color_err.append((s, (formatted, is_error)))

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:

theme = theme_table[self._theme_name]

base_style = theme.as_pygments_style()

tb_highlight = theme.extra_style.get(Token.TbHighlight, self.tb_highlight)

style = stack_data.style_with_executing_node(base_style, tb_highlight)

formatter = Terminal256Formatter(style=style)

else:

formatter = None

options = stack_data.Options(

before=before,

after=after,

pygments_formatter=formatter,

)

# Collect traceback frames and their module sizes.

cf: Optional[TracebackType] = etb

tbs: list[tuple[TracebackType, int]] = []

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

frame_len = get_line_number_of_frame(cf.tb_frame)

if frame_len == 0:

# File not found or not a .py file (e.g. <string> from

# exec()). Check if source is actually available; if not,

# force the fast path so that FrameInfo's "Could not get

# source" fallback is rendered.

try:

inspect.getsourcelines(cf.tb_frame)

except OSError:

frame_len = FAST_THRESHOLD + 1

except OSError:

frame_len = FAST_THRESHOLD + 1

assert cf is not None # narrowing for mypy; guarded by while condition

tbs.append((cf, frame_len))

cf = cf.tb_next

# Group consecutive frames by fast/slow and process each group.

# Consecutive slow frames must be processed together so that

# stack_data can detect RepeatedFrames (recursion collapsing).

FIs: list[FrameInfo] = []

i = 0

while i < len(tbs):

tb, frame_len = tbs[i]

if frame_len > FAST_THRESHOLD:

frame = tb.tb_frame # type: ignore[union-attr]

lineno = frame.f_lineno

code = frame.f_code

filename = code.co_filename

FIs.append(

FrameInfo(

"Raw frame", filename, lineno, frame, code, context=context

)

)

i += 1

else:

# Collect the consecutive run of slow frames

group_start = i

while i < len(tbs) and tbs[i][1] <= FAST_THRESHOLD:

i += 1

# Build set of frame objects in this group for filtering

group_frames = {tbs[j][0].tb_frame for j in range(group_start, i)}

# Process via stack_data starting from the first tb in the group

for sd_fi in stack_data.FrameInfo.stack_data(

tbs[group_start][0], options=options

):

# stack_data follows tb_next through the full chain,

# including IPython frames we skipped during collection.

# Filter those out, but always keep RepeatedFrames.

if isinstance(sd_fi, stack_data.RepeatedFrames) or sd_fi.frame in group_frames:

FIs.append(FrameInfo._from_stack_data_FrameInfo(sd_fi))

return FIs

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