#! /usr/bin/env python3
	"""
	The Python Debugger Pdb
	=======================
	To use the debugger in its simplest form:
	>>> import pdb
	>>> pdb.run('<a statement>')
	The debugger's prompt is '(Pdb) '. This will stop in the first
	function call in <a statement>.
	Alternatively, if a statement terminated with an unhandled exception,
	you can use pdb's post-mortem facility to inspect the contents of the
	traceback:
	>>> <a statement>
	<exception traceback>
	>>> import pdb
	>>> pdb.pm()
	The commands recognized by the debugger are listed in the next
	section. Most can be abbreviated as indicated; e.g., h(elp) means
	that 'help' can be typed as 'h' or 'help' (but not as 'he' or 'hel',
	nor as 'H' or 'Help' or 'HELP'). Optional arguments are enclosed in
	square brackets. Alternatives in the command syntax are separated
	by a vertical bar (|).
	A blank line repeats the previous command literally, except for
	'list', where it lists the next 11 lines.
	Commands that the debugger doesn't recognize are assumed to be Python
	statements and are executed in the context of the program being
	debugged. Python statements can also be prefixed with an exclamation
	point ('!'). This is a powerful way to inspect the program being
	debugged; it is even possible to change variables or call functions.
	When an exception occurs in such a statement, the exception name is
	printed but the debugger's state is not changed.
	The debugger supports aliases, which can save typing. And aliases can
	have parameters (see the alias help entry) which allows one a certain
	level of adaptability to the context under examination.
	Multiple commands may be entered on a single line, separated by the
	pair ';;'. No intelligence is applied to separating the commands; the
	input is split at the first ';;', even if it is in the middle of a
	quoted string.
	If a file ".pdbrc" exists in your home directory or in the current
	directory, it is read in and executed as if it had been typed at the
	debugger prompt. This is particularly useful for aliases. If both
	files exist, the one in the home directory is read first and aliases
	defined there can be overridden by the local file. This behavior can be
	disabled by passing the "readrc=False" argument to the Pdb constructor.
	Aside from aliases, the debugger is not directly programmable; but it
	is implemented as a class from which you can derive your own debugger
	class, which you can make as fancy as you like.
	Debugger commands
	=================
	"""
	# NOTE: the actual command documentation is collected from docstrings of the
	# commands and is appended to __doc__ after the class has been defined.
	import os
	import re
	import sys
	import cmd
	import bdb
	import dis
	import code
	import glob
	import pprint
	import signal
	import inspect
	import traceback
	import linecache
	class Restart(Exception):
	"""Causes a debugger to be restarted for the debugged python program."""
	pass
	__all__ = ["run", "pm", "Pdb", "runeval", "runctx", "runcall", "set_trace",
	"post_mortem", "help"]
	def find_function(funcname, filename):
	cre = re.compile(r'def\s+%s\s*[(]' % re.escape(funcname))
	try:
	fp = open(filename)
	except OSError:
	return None
	# consumer of this info expects the first line to be 1
	with fp:
	for lineno, line in enumerate(fp, start=1):
	if cre.match(line):
	return funcname, filename, lineno
	return None
	def getsourcelines(obj):
	lines, lineno = inspect.findsource(obj)
	if inspect.isframe(obj) and obj.f_globals is obj.f_locals:
	# must be a module frame: do not try to cut a block out of it
	return lines, 1
	elif inspect.ismodule(obj):
	return lines, 1
	return inspect.getblock(lines[lineno:]), lineno+1
	def lasti2lineno(code, lasti):
	linestarts = list(dis.findlinestarts(code))
	linestarts.reverse()
	for i, lineno in linestarts:
	if lasti >= i:
	return lineno
	return 0
	class _rstr(str):
	"""String that doesn't quote its repr."""
	def __repr__(self):
	return self
	# Interaction prompt line will separate file and call info from code
	# text using value of line_prefix string. A newline and arrow may
	# be to your liking. You can set it once pdb is imported using the
	# command "pdb.line_prefix = '\n% '".
	# line_prefix = ': ' # Use this to get the old situation back
	line_prefix = '\n-> ' # Probably a better default
	class Pdb(bdb.Bdb, cmd.Cmd):
	_previous_sigint_handler = None
	def __init__(self, completekey='tab', stdin=None, stdout=None, skip=None,
	nosigint=False, readrc=True):
	bdb.Bdb.__init__(self, skip=skip)
	cmd.Cmd.__init__(self, completekey, stdin, stdout)
	if stdout:
	self.use_rawinput = 0
	self.prompt = '(Pdb) '
	self.aliases = {}
	self.displaying = {}
	self.mainpyfile = ''
	self._wait_for_mainpyfile = False
	self.tb_lineno = {}
	# Try to load readline if it exists
	try:
	import readline
	# remove some common file name delimiters
	readline.set_completer_delims(' \t\n`@#$%^&*()=+[{]}\\|;:\'",<>?')
	except ImportError:
	pass
	self.allow_kbdint = False
	self.nosigint = nosigint
	# Read $HOME/.pdbrc and ./.pdbrc
	self.rcLines = []
	if readrc:
	if 'HOME' in os.environ:
	envHome = os.environ['HOME']
	try:
	with open(os.path.join(envHome, ".pdbrc")) as rcFile:
	self.rcLines.extend(rcFile)
	except OSError:
	pass
	try:
	with open(".pdbrc") as rcFile:
	self.rcLines.extend(rcFile)
	except OSError:
	pass
	self.commands = {} # associates a command list to breakpoint numbers
	self.commands_doprompt = {} # for each bp num, tells if the prompt
	# must be disp. after execing the cmd list
	self.commands_silent = {} # for each bp num, tells if the stack trace
	# must be disp. after execing the cmd list
	self.commands_defining = False # True while in the process of defining
	# a command list
	self.commands_bnum = None # The breakpoint number for which we are
	# defining a list
	def sigint_handler(self, signum, frame):
	if self.allow_kbdint:
	raise KeyboardInterrupt
	self.message("\nProgram interrupted. (Use 'cont' to resume).")
	self.set_step()
	self.set_trace(frame)
	def reset(self):
	bdb.Bdb.reset(self)
	self.forget()
	def forget(self):
	self.lineno = None
	self.stack = []
	self.curindex = 0
	self.curframe = None
	self.tb_lineno.clear()
	def setup(self, f, tb):
	self.forget()
	self.stack, self.curindex = self.get_stack(f, tb)
	while tb:
	# when setting up post-mortem debugging with a traceback, save all
	# the original line numbers to be displayed along the current line
	# numbers (which can be different, e.g. due to finally clauses)
	lineno = lasti2lineno(tb.tb_frame.f_code, tb.tb_lasti)
	self.tb_lineno[tb.tb_frame] = lineno
	tb = tb.tb_next
	self.curframe = self.stack[self.curindex][0]
	# The f_locals dictionary is updated from the actual frame
	# locals whenever the .f_locals accessor is called, so we
	# cache it here to ensure that modifications are not overwritten.
	self.curframe_locals = self.curframe.f_locals
	return self.execRcLines()
	# Can be executed earlier than 'setup' if desired
	def execRcLines(self):
	if not self.rcLines:
	return
	# local copy because of recursion
	rcLines = self.rcLines
	rcLines.reverse()
	# execute every line only once
	self.rcLines = []
	while rcLines:
	line = rcLines.pop().strip()
	if line and line[0] != '#':
	if self.onecmd(line):
	# if onecmd returns True, the command wants to exit
	# from the interaction, save leftover rc lines
	# to execute before next interaction
	self.rcLines += reversed(rcLines)
	return True
	# Override Bdb methods
	def user_call(self, frame, argument_list):
	"""This method is called when there is the remote possibility
	that we ever need to stop in this function."""
	if self._wait_for_mainpyfile:
	return
	if self.stop_here(frame):
	self.message('--Call--')
	self.interaction(frame, None)
	def user_line(self, frame):
	"""This function is called when we stop or break at this line."""
	if self._wait_for_mainpyfile:
	if (self.mainpyfile != self.canonic(frame.f_code.co_filename)
	or frame.f_lineno <= 0):
	return
	self._wait_for_mainpyfile = False
	if self.bp_commands(frame):
	self.interaction(frame, None)
	def bp_commands(self, frame):
	"""Call every command that was set for the current active breakpoint
	(if there is one).
	Returns True if the normal interaction function must be called,
	False otherwise."""
	# self.currentbp is set in bdb in Bdb.break_here if a breakpoint was hit
	if getattr(self, "currentbp", False) and \
	self.currentbp in self.commands:
	currentbp = self.currentbp
	self.currentbp = 0
	lastcmd_back = self.lastcmd
	self.setup(frame, None)
	for line in self.commands[currentbp]:
	self.onecmd(line)
	self.lastcmd = lastcmd_back
	if not self.commands_silent[currentbp]:
	self.print_stack_entry(self.stack[self.curindex])
	if self.commands_doprompt[currentbp]:
	self._cmdloop()
	self.forget()
	return
	return 1
	def user_return(self, frame, return_value):
	"""This function is called when a return trap is set here."""
	if self._wait_for_mainpyfile:
	return
	frame.f_locals['__return__'] = return_value
	self.message('--Return--')
	self.interaction(frame, None)
	def user_exception(self, frame, exc_info):
	"""This function is called if an exception occurs,
	but only if we are to stop at or just below this level."""
	if self._wait_for_mainpyfile:
	return
	exc_type, exc_value, exc_traceback = exc_info
	frame.f_locals['__exception__'] = exc_type, exc_value
	# An 'Internal StopIteration' exception is an exception debug event
	# issued by the interpreter when handling a subgenerator run with
	# 'yield from' or a generator controlled by a for loop. No exception has
	# actually occurred in this case. The debugger uses this debug event to
	# stop when the debuggee is returning from such generators.
	prefix = 'Internal ' if (not exc_traceback
	and exc_type is StopIteration) else ''
	self.message('%s%s' % (prefix,
	traceback.format_exception_only(exc_type, exc_value)[-1].strip()))
	self.interaction(frame, exc_traceback)
	# General interaction function
	def _cmdloop(self):
	while True:
	try:
	# keyboard interrupts allow for an easy way to cancel
	# the current command, so allow them during interactive input
	self.allow_kbdint = True
	self.cmdloop()
	self.allow_kbdint = False
	break
	except KeyboardInterrupt:
	self.message('--KeyboardInterrupt--')
	# Called before loop, handles display expressions
	def preloop(self):
	displaying = self.displaying.get(self.curframe)
	if displaying:
	for expr, oldvalue in displaying.items():
	newvalue = self._getval_except(expr)
	# check for identity first; this prevents custom __eq__ to
	# be called at every loop, and also prevents instances whose
	# fields are changed to be displayed
	if newvalue is not oldvalue and newvalue != oldvalue:
	displaying[expr] = newvalue
	self.message('display %s: %r [old: %r]' %
	(expr, newvalue, oldvalue))
	def interaction(self, frame, traceback):
	# Restore the previous signal handler at the Pdb prompt.
	if Pdb._previous_sigint_handler:
	signal.signal(signal.SIGINT, Pdb._previous_sigint_handler)
	Pdb._previous_sigint_handler = None
	if self.setup(frame, traceback):
	# no interaction desired at this time (happens if .pdbrc contains
	# a command like "continue")
	self.forget()
	return
	self.print_stack_entry(self.stack[self.curindex])
	self._cmdloop()
	self.forget()
	def displayhook(self, obj):
	"""Custom displayhook for the exec in default(), which prevents
	assignment of the _ variable in the builtins.
	"""
	# reproduce the behavior of the standard displayhook, not printing None
	if obj is not None:
	self.message(repr(obj))
	def default(self, line):
	if line[:1] == '!': line = line[1:]
	locals = self.curframe_locals
	globals = self.curframe.f_globals
	try:
	code = compile(line + '\n', '<stdin>', 'single')
	save_stdout = sys.stdout
	save_stdin = sys.stdin
	save_displayhook = sys.displayhook
	try:
	sys.stdin = self.stdin
	sys.stdout = self.stdout
	sys.displayhook = self.displayhook
	exec(code, globals, locals)
	finally:
	sys.stdout = save_stdout
	sys.stdin = save_stdin
	sys.displayhook = save_displayhook
	except:
	exc_info = sys.exc_info()[:2]
	self.error(traceback.format_exception_only(*exc_info)[-1].strip())
	def precmd(self, line):
	"""Handle alias expansion and ';;' separator."""
	if not line.strip():
	return line
	args = line.split()
	while args[0] in self.aliases:
	line = self.aliases[args[0]]
	ii = 1
	for tmpArg in args[1:]:
	line = line.replace("%" + str(ii),
	tmpArg)
	ii += 1
	line = line.replace("%*", ' '.join(args[1:]))
	args = line.split()
	# split into ';;' separated commands
	# unless it's an alias command
	if args[0] != 'alias':
	marker = line.find(';;')
	if marker >= 0:
	# queue up everything after marker
	next = line[marker+2:].lstrip()
	self.cmdqueue.append(next)
	line = line[:marker].rstrip()
	return line
	def onecmd(self, line):
	"""Interpret the argument as though it had been typed in response
	to the prompt.
	Checks whether this line is typed at the normal prompt or in
	a breakpoint command list definition.
	"""
	if not self.commands_defining:
	return cmd.Cmd.onecmd(self, line)
	else:
	return self.handle_command_def(line)
	def handle_command_def(self, line):
	"""Handles one command line during command list definition."""
	cmd, arg, line = self.parseline(line)
	if not cmd:
	return
	if cmd == 'silent':
	self.commands_silent[self.commands_bnum] = True
	return # continue to handle other cmd def in the cmd list
	elif cmd == 'end':
	self.cmdqueue = []
	return 1 # end of cmd list
	cmdlist = self.commands[self.commands_bnum]
	if arg:
	cmdlist.append(cmd+' '+arg)
	else:
	cmdlist.append(cmd)
	# Determine if we must stop
	try:
	func = getattr(self, 'do_' + cmd)
	except AttributeError:
	func = self.default
	# one of the resuming commands
	if func.__name__ in self.commands_resuming:
	self.commands_doprompt[self.commands_bnum] = False
	self.cmdqueue = []
	return 1
	return
	# interface abstraction functions
	def message(self, msg):
	print(msg, file=self.stdout)
	def error(self, msg):
	print('***', msg, file=self.stdout)
	# Generic completion functions. Individual complete_foo methods can be
	# assigned below to one of these functions.
	def _complete_location(self, text, line, begidx, endidx):
	# Complete a file/module/function location for break/tbreak/clear.
	if line.strip().endswith((':', ',')):
	# Here comes a line number or a condition which we can't complete.
	return []
	# First, try to find matching functions (i.e. expressions).
	try:
	ret = self._complete_expression(text, line, begidx, endidx)
	except Exception:
	ret = []
	# Then, try to complete file names as well.
	globs = glob.glob(text + '*')
	for fn in globs:
	if os.path.isdir(fn):
	ret.append(fn + '/')
	elif os.path.isfile(fn) and fn.lower().endswith(('.py', '.pyw')):
	ret.append(fn + ':')
	return ret
	def _complete_bpnumber(self, text, line, begidx, endidx):
	# Complete a breakpoint number. (This would be more helpful if we could
	# display additional info along with the completions, such as file/line
	# of the breakpoint.)
	return [str(i) for i, bp in enumerate(bdb.Breakpoint.bpbynumber)
	if bp is not None and str(i).startswith(text)]
	def _complete_expression(self, text, line, begidx, endidx):
	# Complete an arbitrary expression.
	if not self.curframe:
	return []
	# Collect globals and locals. It is usually not really sensible to also
	# complete builtins, and they clutter the namespace quite heavily, so we
	# leave them out.
	ns = {**self.curframe.f_globals, **self.curframe_locals}
	if '.' in text:
	# Walk an attribute chain up to the last part, similar to what
	# rlcompleter does. This will bail if any of the parts are not
	# simple attribute access, which is what we want.
	dotted = text.split('.')
	try:
	obj = ns[dotted[0]]
	for part in dotted[1:-1]:
	obj = getattr(obj, part)
	except (KeyError, AttributeError):
	return []
	prefix = '.'.join(dotted[:-1]) + '.'
	return [prefix + n for n in dir(obj) if n.startswith(dotted[-1])]
	else:
	# Complete a simple name.
	return [n for n in ns.keys() if n.startswith(text)]
	# Command definitions, called by cmdloop()
	# The argument is the remaining string on the command line
	# Return true to exit from the command loop
	def do_commands(self, arg):
	"""commands [bpnumber]
	(com) ...
	(com) end
	(Pdb)
	Specify a list of commands for breakpoint number bpnumber.
	The commands themselves are entered on the following lines.
	Type a line containing just 'end' to terminate the commands.
	The commands are executed when the breakpoint is hit.
	To remove all commands from a breakpoint, type commands and
	follow it immediately with end; that is, give no commands.
	With no bpnumber argument, commands refers to the last
	breakpoint set.
	You can use breakpoint commands to start your program up
	again. Simply use the continue command, or step, or any other
	command that resumes execution.
	Specifying any command resuming execution (currently continue,
	step, next, return, jump, quit and their abbreviations)
	terminates the command list (as if that command was
	immediately followed by end). This is because any time you
	resume execution (even with a simple next or step), you may
	encounter another breakpoint -- which could have its own
	command list, leading to ambiguities about which list to
	execute.
	If you use the 'silent' command in the command list, the usual
	message about stopping at a breakpoint is not printed. This
	may be desirable for breakpoints that are to print a specific
	message and then continue. If none of the other commands
	print anything, you will see no sign that the breakpoint was
	reached.
	"""
	if not arg:
	bnum = len(bdb.Breakpoint.bpbynumber) - 1
	else:
	try:
	bnum = int(arg)
	except:
	self.error("Usage: commands [bnum]\n ...\n end")
	return
	self.commands_bnum = bnum
	# Save old definitions for the case of a keyboard interrupt.
	if bnum in self.commands:
	old_command_defs = (self.commands[bnum],
	self.commands_doprompt[bnum],
	self.commands_silent[bnum])
	else:
	old_command_defs = None
	self.commands[bnum] = []
	self.commands_doprompt[bnum] = True
	self.commands_silent[bnum] = False
	prompt_back = self.prompt
	self.prompt = '(com) '
	self.commands_defining = True
	try:
	self.cmdloop()
	except KeyboardInterrupt:
	# Restore old definitions.
	if old_command_defs:
	self.commands[bnum] = old_command_defs[0]
	self.commands_doprompt[bnum] = old_command_defs[1]
	self.commands_silent[bnum] = old_command_defs[2]
	else:
	del self.commands[bnum]
	del self.commands_doprompt[bnum]
	del self.commands_silent[bnum]
	self.error('command definition aborted, old commands restored')
	finally:
	self.commands_defining = False
	self.prompt = prompt_back
	complete_commands = _complete_bpnumber
	def do_break(self, arg, temporary = 0):
	"""b(reak) [ ([filename:]lineno | function) [, condition] ]
	Without argument, list all breaks.
	With a line number argument, set a break at this line in the
	current file. With a function name, set a break at the first
	executable line of that function. If a second argument is
	present, it is a string specifying an expression which must
	evaluate to true before the breakpoint is honored.
	The line number may be prefixed with a filename and a colon,
	to specify a breakpoint in another file (probably one that
	hasn't been loaded yet). The file is searched for on
	sys.path; the .py suffix may be omitted.
	"""
	if not arg:
	if self.breaks: # There's at least one
	self.message("Num Type Disp Enb Where")
	for bp in bdb.Breakpoint.bpbynumber:
	if bp:
	self.message(bp.bpformat())
	return
	# parse arguments; comma has lowest precedence
	# and cannot occur in filename
	filename = None
	lineno = None
	cond = None
	comma = arg.find(',')
	if comma > 0:
	# parse stuff after comma: "condition"
	cond = arg[comma+1:].lstrip()
	arg = arg[:comma].rstrip()
	# parse stuff before comma: [filename:]lineno | function
	colon = arg.rfind(':')
	funcname = None
	if colon >= 0:
	filename = arg[:colon].rstrip()
	f = self.lookupmodule(filename)
	if not f:
	self.error('%r not found from sys.path' % filename)
	return
	else:
	filename = f
	arg = arg[colon+1:].lstrip()
	try:
	lineno = int(arg)
	except ValueError:
	self.error('Bad lineno: %s' % arg)
	return
	else:
	# no colon; can be lineno or function
	try:
	lineno = int(arg)
	except ValueError:
	try:
	func = eval(arg,
	self.curframe.f_globals,
	self.curframe_locals)
	except:
	func = arg
	try:
	if hasattr(func, '__func__'):
	func = func.__func__
	code = func.__code__
	#use co_name to identify the bkpt (function names
	#could be aliased, but co_name is invariant)
	funcname = code.co_name
	lineno = code.co_firstlineno
	filename = code.co_filename
	except:
	# last thing to try
	(ok, filename, ln) = self.lineinfo(arg)
	if not ok:
	self.error('The specified object %r is not a function '
	'or was not found along sys.path.' % arg)
	return
	funcname = ok # ok contains a function name
	lineno = int(ln)
	if not filename:
	filename = self.defaultFile()
	# Check for reasonable breakpoint
	line = self.checkline(filename, lineno)
	if line:
	# now set the break point
	err = self.set_break(filename, line, temporary, cond, funcname)
	if err:
	self.error(err)
	else:
	bp = self.get_breaks(filename, line)[-1]
	self.message("Breakpoint %d at %s:%d" %
	(bp.number, bp.file, bp.line))
	# To be overridden in derived debuggers
	def defaultFile(self):
	"""Produce a reasonable default."""
	filename = self.curframe.f_code.co_filename
	if filename == '<string>' and self.mainpyfile:
	filename = self.mainpyfile
	return filename
	do_b = do_break
	complete_break = _complete_location
	complete_b = _complete_location
	def do_tbreak(self, arg):
	"""tbreak [ ([filename:]lineno | function) [, condition] ]
	Same arguments as break, but sets a temporary breakpoint: it
	is automatically deleted when first hit.
	"""
	self.do_break(arg, 1)
	complete_tbreak = _complete_location
	def lineinfo(self, identifier):
	failed = (None, None, None)
	# Input is identifier, may be in single quotes
	idstring = identifier.split("'")
	if len(idstring) == 1:
	# not in single quotes
	id = idstring[0].strip()
	elif len(idstring) == 3:
	# quoted
	id = idstring[1].strip()
	else:
	return failed
	if id == '': return failed
	parts = id.split('.')
	# Protection for derived debuggers
	if parts[0] == 'self':
	del parts[0]
	if len(parts) == 0:
	return failed
	# Best first guess at file to look at
	fname = self.defaultFile()
	if len(parts) == 1:
	item = parts[0]
	else:
	# More than one part.
	# First is module, second is method/class
	f = self.lookupmodule(parts[0])
	if f:
	fname = f
	item = parts[1]
	answer = find_function(item, fname)
	return answer or failed
	def checkline(self, filename, lineno):
	"""Check whether specified line seems to be executable.
	Return `lineno` if it is, 0 if not (e.g. a docstring, comment, blank
	line or EOF). Warning: testing is not comprehensive.
	"""
	# this method should be callable before starting debugging, so default
	# to "no globals" if there is no current frame
	globs = self.curframe.f_globals if hasattr(self, 'curframe') else None
	line = linecache.getline(filename, lineno, globs)
	if not line:
	self.message('End of file')
	return 0
	line = line.strip()
	# Don't allow setting breakpoint at a blank line
	if (not line or (line[0] == '#') or
	(line[:3] == '"""') or line[:3] == "'''"):
	self.error('Blank or comment')
	return 0
	return lineno
	def do_enable(self, arg):
	"""enable bpnumber [bpnumber ...]
	Enables the breakpoints given as a space separated list of
	breakpoint numbers.
	"""
	args = arg.split()
	for i in args:
	try:
	bp = self.get_bpbynumber(i)
	except ValueError as err:
	self.error(err)
	else:
	bp.enable()
	self.message('Enabled %s' % bp)
	complete_enable = _complete_bpnumber
	def do_disable(self, arg):
	"""disable bpnumber [bpnumber ...]
	Disables the breakpoints given as a space separated list of
	breakpoint numbers. Disabling a breakpoint means it cannot
	cause the program to stop execution, but unlike clearing a
	breakpoint, it remains in the list of breakpoints and can be
	(re-)enabled.
	"""
	args = arg.split()
	for i in args:
	try:
	bp = self.get_bpbynumber(i)
	except ValueError as err:
	self.error(err)
	else:
	bp.disable()
	self.message('Disabled %s' % bp)
	complete_disable = _complete_bpnumber
	def do_condition(self, arg):
	"""condition bpnumber [condition]
	Set a new condition for the breakpoint, an expression which
	must evaluate to true before the breakpoint is honored. If
	condition is absent, any existing condition is removed; i.e.,
	the breakpoint is made unconditional.
	"""
	args = arg.split(' ', 1)
	try:
	cond = args[1]
	except IndexError:
	cond = None
	try:
	bp = self.get_bpbynumber(args[0].strip())
	except IndexError:
	self.error('Breakpoint number expected')
	except ValueError as err:
	self.error(err)
	else:
	bp.cond = cond
	if not cond:
	self.message('Breakpoint %d is now unconditional.' % bp.number)
	else:
	self.message('New condition set for breakpoint %d.' % bp.number)
	complete_condition = _complete_bpnumber
	def do_ignore(self, arg):
	"""ignore bpnumber [count]
	Set the ignore count for the given breakpoint number. If
	count is omitted, the ignore count is set to 0. A breakpoint
	becomes active when the ignore count is zero. When non-zero,
	the count is decremented each time the breakpoint is reached
	and the breakpoint is not disabled and any associated
	condition evaluates to true.
	"""
	args = arg.split()
	try:
	count = int(args[1].strip())
	except:
	count = 0
	try:
	bp = self.get_bpbynumber(args[0].strip())
	except IndexError:
	self.error('Breakpoint number expected')
	except ValueError as err:
	self.error(err)
	else:
	bp.ignore = count
	if count > 0:
	if count > 1:
	countstr = '%d crossings' % count
	else:
	countstr = '1 crossing'
	self.message('Will ignore next %s of breakpoint %d.' %
	(countstr, bp.number))
	else:
	self.message('Will stop next time breakpoint %d is reached.'
	% bp.number)
	complete_ignore = _complete_bpnumber
	def do_clear(self, arg):
	"""cl(ear) filename:lineno\ncl(ear) [bpnumber [bpnumber...]]
	With a space separated list of breakpoint numbers, clear
	those breakpoints. Without argument, clear all breaks (but
	first ask confirmation). With a filename:lineno argument,
	clear all breaks at that line in that file.
	"""
	if not arg:
	try:
	reply = input('Clear all breaks? ')
	except EOFError:
	reply = 'no'
	reply = reply.strip().lower()
	if reply in ('y', 'yes'):
	bplist = [bp for bp in bdb.Breakpoint.bpbynumber if bp]
	self.clear_all_breaks()
	for bp in bplist:
	self.message('Deleted %s' % bp)
	return
	if ':' in arg:
	# Make sure it works for "clear C:\foo\bar.py:12"
	i = arg.rfind(':')
	filename = arg[:i]
	arg = arg[i+1:]
	try:
	lineno = int(arg)
	except ValueError:
	err = "Invalid line number (%s)" % arg
	else:
	bplist = self.get_breaks(filename, lineno)
	err = self.clear_break(filename, lineno)
	if err:
	self.error(err)
	else:
	for bp in bplist:
	self.message('Deleted %s' % bp)
	return
	numberlist = arg.split()
	for i in numberlist:
	try:
	bp = self.get_bpbynumber(i)
	except ValueError as err:
	self.error(err)
	else:
	self.clear_bpbynumber(i)
	self.message('Deleted %s' % bp)
	do_cl = do_clear # 'c' is already an abbreviation for 'continue'
	complete_clear = _complete_location
	complete_cl = _complete_location
	def do_where(self, arg):
	"""w(here)
	Print a stack trace, with the most recent frame at the bottom.
	An arrow indicates the "current frame", which determines the
	context of most commands. 'bt' is an alias for this command.
	"""
	self.print_stack_trace()
	do_w = do_where
	do_bt = do_where
	def _select_frame(self, number):
	assert 0 <= number < len(self.stack)
	self.curindex = number
	self.curframe = self.stack[self.curindex][0]
	self.curframe_locals = self.curframe.f_locals
	self.print_stack_entry(self.stack[self.curindex])
	self.lineno = None
	def do_up(self, arg):
	"""u(p) [count]
	Move the current frame count (default one) levels up in the
	stack trace (to an older frame).
	"""
	if self.curindex == 0:
	self.error('Oldest frame')
	return
	try:
	count = int(arg or 1)
	except ValueError:
	self.error('Invalid frame count (%s)' % arg)
	return
	if count < 0:
	newframe = 0
	else:
	newframe = max(0, self.curindex - count)
	self._select_frame(newframe)
	do_u = do_up
	def do_down(self, arg):
	"""d(own) [count]
	Move the current frame count (default one) levels down in the
	stack trace (to a newer frame).
	"""
	if self.curindex + 1 == len(self.stack):
	self.error('Newest frame')
	return
	try:
	count = int(arg or 1)
	except ValueError:
	self.error('Invalid frame count (%s)' % arg)
	return
	if count < 0:
	newframe = len(self.stack) - 1
	else:
	newframe = min(len(self.stack) - 1, self.curindex + count)
	self._select_frame(newframe)
	do_d = do_down
	def do_until(self, arg):
	"""unt(il) [lineno]
	Without argument, continue execution until the line with a
	number greater than the current one is reached. With a line
	number, continue execution until a line with a number greater
	or equal to that is reached. In both cases, also stop when
	the current frame returns.
	"""
	if arg:
	try:
	lineno = int(arg)
	except ValueError:
	self.error('Error in argument: %r' % arg)
	return
	if lineno <= self.curframe.f_lineno:
	self.error('"until" line number is smaller than current '
	'line number')
	return
	else:
	lineno = None
	self.set_until(self.curframe, lineno)
	return 1
	do_unt = do_until
	def do_step(self, arg):
	"""s(tep)
	Execute the current line, stop at the first possible occasion
	(either in a function that is called or in the current
	function).
	"""
	self.set_step()
	return 1
	do_s = do_step
	def do_next(self, arg):
	"""n(ext)
	Continue execution until the next line in the current function
	is reached or it returns.
	"""
	self.set_next(self.curframe)
	return 1
	do_n = do_next
	def do_run(self, arg):
	"""run [args...]
	Restart the debugged python program. If a string is supplied
	it is split with "shlex", and the result is used as the new
	sys.argv. History, breakpoints, actions and debugger options
	are preserved. "restart" is an alias for "run".
	"""
	if arg:
	import shlex
	argv0 = sys.argv[0:1]
	sys.argv = shlex.split(arg)
	sys.argv[:0] = argv0
	# this is caught in the main debugger loop
	raise Restart
	do_restart = do_run
	def do_return(self, arg):
	"""r(eturn)
	Continue execution until the current function returns.
	"""
	self.set_return(self.curframe)
	return 1
	do_r = do_return
	def do_continue(self, arg):
	"""c(ont(inue))
	Continue execution, only stop when a breakpoint is encountered.
	"""
	if not self.nosigint:
	try:
	Pdb._previous_sigint_handler = \
	signal.signal(signal.SIGINT, self.sigint_handler)
	except ValueError:
	# ValueError happens when do_continue() is invoked from
	# a non-main thread in which case we just continue without
	# SIGINT set. Would printing a message here (once) make
	# sense?
	pass
	self.set_continue()
	return 1
	do_c = do_cont = do_continue
	def do_jump(self, arg):
	"""j(ump) lineno
	Set the next line that will be executed. Only available in
	the bottom-most frame. This lets you jump back and execute
	code again, or jump forward to skip code that you don't want
	to run.
	It should be noted that not all jumps are allowed -- for
	instance it is not possible to jump into the middle of a
	for loop or out of a finally clause.
	"""
	if self.curindex + 1 != len(self.stack):
	self.error('You can only jump within the bottom frame')
	return
	try:
	arg = int(arg)
	except ValueError:
	self.error("The 'jump' command requires a line number")
	else:
	try:
	# Do the jump, fix up our copy of the stack, and display the
	# new position
	self.curframe.f_lineno = arg
	self.stack[self.curindex] = self.stack[self.curindex][0], arg
	self.print_stack_entry(self.stack[self.curindex])
	except ValueError as e:
	self.error('Jump failed: %s' % e)
	do_j = do_jump
	def do_debug(self, arg):
	"""debug code
	Enter a recursive debugger that steps through the code
	argument (which is an arbitrary expression or statement to be
	executed in the current environment).
	"""
	sys.settrace(None)
	globals = self.curframe.f_globals
	locals = self.curframe_locals
	p = Pdb(self.completekey, self.stdin, self.stdout)
	p.prompt = "(%s) " % self.prompt.strip()
	self.message("ENTERING RECURSIVE DEBUGGER")
	try:
	sys.call_tracing(p.run, (arg, globals, locals))
	except Exception:
	exc_info = sys.exc_info()[:2]
	self.error(traceback.format_exception_only(*exc_info)[-1].strip())
	self.message("LEAVING RECURSIVE DEBUGGER")
	sys.settrace(self.trace_dispatch)
	self.lastcmd = p.lastcmd
	complete_debug = _complete_expression
	def do_quit(self, arg):
	"""q(uit)\nexit
	Quit from the debugger. The program being executed is aborted.
	"""
	self._user_requested_quit = True
	self.set_quit()
	return 1
	do_q = do_quit
	do_exit = do_quit
	def do_EOF(self, arg):
	"""EOF
	Handles the receipt of EOF as a command.
	"""
	self.message('')
	self._user_requested_quit = True
	self.set_quit()
	return 1
	def do_args(self, arg):
	"""a(rgs)
	Print the argument list of the current function.
	"""
	co = self.curframe.f_code
	dict = self.curframe_locals
	n = co.co_argcount + co.co_posonlyargcount + co.co_kwonlyargcount
	if co.co_flags & inspect.CO_VARARGS: n = n+1
	if co.co_flags & inspect.CO_VARKEYWORDS: n = n+1
	for i in range(n):
	name = co.co_varnames[i]
	if name in dict:
	self.message('%s = %r' % (name, dict[name]))
	else:
	self.message('%s = *** undefined ***' % (name,))
	do_a = do_args
	def do_retval(self, arg):
	"""retval
	Print the return value for the last return of a function.
	"""
	if '__return__' in self.curframe_locals:
	self.message(repr(self.curframe_locals['__return__']))
	else:
	self.error('Not yet returned!')
	do_rv = do_retval
	def _getval(self, arg):
	try:
	return eval(arg, self.curframe.f_globals, self.curframe_locals)
	except:
	exc_info = sys.exc_info()[:2]
	self.error(traceback.format_exception_only(*exc_info)[-1].strip())
	raise
	def _getval_except(self, arg, frame=None):
	try:
	if frame is None:
	return eval(arg, self.curframe.f_globals, self.curframe_locals)
	else:
	return eval(arg, frame.f_globals, frame.f_locals)
	except:
	exc_info = sys.exc_info()[:2]
	err = traceback.format_exception_only(*exc_info)[-1].strip()
	return _rstr('** raised %s **' % err)
	def do_p(self, arg):
	"""p expression
	Print the value of the expression.
	"""
	try:
	self.message(repr(self._getval(arg)))
	except:
	pass
	def do_pp(self, arg):
	"""pp expression
	Pretty-print the value of the expression.
	"""
	try:
	self.message(pprint.pformat(self._getval(arg)))
	except:
	pass
	complete_print = _complete_expression
	complete_p = _complete_expression
	complete_pp = _complete_expression
	def do_list(self, arg):
	"""l(ist) [first [,last] | .]
	List source code for the current file. Without arguments,
	list 11 lines around the current line or continue the previous
	listing. With . as argument, list 11 lines around the current
	line. With one argument, list 11 lines starting at that line.
	With two arguments, list the given range; if the second
	argument is less than the first, it is a count.
	The current line in the current frame is indicated by "->".
	If an exception is being debugged, the line where the
	exception was originally raised or propagated is indicated by
	">>", if it differs from the current line.
	"""
	self.lastcmd = 'list'
	last = None
	if arg and arg != '.':
	try:
	if ',' in arg:
	first, last = arg.split(',')
	first = int(first.strip())
	last = int(last.strip())
	if last < first:
	# assume it's a count
	last = first + last
	else:
	first = int(arg.strip())
	first = max(1, first - 5)
	except ValueError:
	self.error('Error in argument: %r' % arg)
	return
	elif self.lineno is None or arg == '.':
	first = max(1, self.curframe.f_lineno - 5)
	else:
	first = self.lineno + 1
	if last is None:
	last = first + 10
	filename = self.curframe.f_code.co_filename
	breaklist = self.get_file_breaks(filename)
	try:
	lines = linecache.getlines(filename, self.curframe.f_globals)
	self._print_lines(lines[first-1:last], first, breaklist,
	self.curframe)
	self.lineno = min(last, len(lines))
	if len(lines) < last:
	self.message('[EOF]')
	except KeyboardInterrupt:
	pass
	do_l = do_list
	def do_longlist(self, arg):
	"""longlist | ll
	List the whole source code for the current function or frame.
	"""
	filename = self.curframe.f_code.co_filename
	breaklist = self.get_file_breaks(filename)
	try:
	lines, lineno = getsourcelines(self.curframe)
	except OSError as err:
	self.error(err)
	return
	self._print_lines(lines, lineno, breaklist, self.curframe)
	do_ll = do_longlist
	def do_source(self, arg):
	"""source expression
	Try to get source code for the given object and display it.
	"""
	try:
	obj = self._getval(arg)
	except:
	return
	try:
	lines, lineno = getsourcelines(obj)
	except (OSError, TypeError) as err:
	self.error(err)
	return
	self._print_lines(lines, lineno)
	complete_source = _complete_expression
	def _print_lines(self, lines, start, breaks=(), frame=None):
	"""Print a range of lines."""
	if frame:
	current_lineno = frame.f_lineno
	exc_lineno = self.tb_lineno.get(frame, -1)
	else:
	current_lineno = exc_lineno = -1
	for lineno, line in enumerate(lines, start):
	s = str(lineno).rjust(3)
	if len(s) < 4:
	s += ' '
	if lineno in breaks:
	s += 'B'
	else:
	s += ' '
	if lineno == current_lineno:
	s += '->'
	elif lineno == exc_lineno:
	s += '>>'
	self.message(s + '\t' + line.rstrip())
	def do_whatis(self, arg):
	"""whatis arg
	Print the type of the argument.
	"""
	try:
	value = self._getval(arg)
	except:
	# _getval() already printed the error
	return
	code = None
	# Is it a function?
	try:
	code = value.__code__
	except Exception:
	pass
	if code:
	self.message('Function %s' % code.co_name)
	return
	# Is it an instance method?
	try:
	code = value.__func__.__code__
	except Exception:
	pass
	if code:
	self.message('Method %s' % code.co_name)
	return
	# Is it a class?
	if value.__class__ is type:
	self.message('Class %s.%s' % (value.__module__, value.__qualname__))
	return
	# None of the above...
	self.message(type(value))
	complete_whatis = _complete_expression
	def do_display(self, arg):
	"""display [expression]
	Display the value of the expression if it changed, each time execution
	stops in the current frame.
	Without expression, list all display expressions for the current frame.
	"""
	if not arg:
	self.message('Currently displaying:')
	for item in self.displaying.get(self.curframe, {}).items():
	self.message('%s: %r' % item)
	else:
	val = self._getval_except(arg)
	self.displaying.setdefault(self.curframe, {})[arg] = val
	self.message('display %s: %r' % (arg, val))
	complete_display = _complete_expression
	def do_undisplay(self, arg):
	"""undisplay [expression]
	Do not display the expression any more in the current frame.
	Without expression, clear all display expressions for the current frame.
	"""
	if arg:
	try:
	del self.displaying.get(self.curframe, {})[arg]
	except KeyError:
	self.error('not displaying %s' % arg)
	else:
	self.displaying.pop(self.curframe, None)
	def complete_undisplay(self, text, line, begidx, endidx):
	return [e for e in self.displaying.get(self.curframe, {})
	if e.startswith(text)]
	def do_interact(self, arg):
	"""interact
	Start an interactive interpreter whose global namespace
	contains all the (global and local) names found in the current scope.
	"""
	ns = {**self.curframe.f_globals, **self.curframe_locals}
	code.interact("*interactive*", local=ns)
	def do_alias(self, arg):
	"""alias [name [command [parameter parameter ...] ]]
	Create an alias called 'name' that executes 'command'. The
	command must *not* be enclosed in quotes. Replaceable
	parameters can be indicated by %1, %2, and so on, while %* is
	replaced by all the parameters. If no command is given, the
	current alias for name is shown. If no name is given, all
	aliases are listed.
	Aliases may be nested and can contain anything that can be
	legally typed at the pdb prompt. Note! You *can* override
	internal pdb commands with aliases! Those internal commands
	are then hidden until the alias is removed. Aliasing is
	recursively applied to the first word of the command line; all
	other words in the line are left alone.
	As an example, here are two useful aliases (especially when
	placed in the .pdbrc file):
	# Print instance variables (usage "pi classInst")
	alias pi for k in %1.__dict__.keys(): print("%1.",k,"=",%1.__dict__[k])
	# Print instance variables in self
	alias ps pi self
	"""
	args = arg.split()
	if len(args) == 0:
	keys = sorted(self.aliases.keys())
	for alias in keys:
	self.message("%s = %s" % (alias, self.aliases[alias]))
	return
	if args[0] in self.aliases and len(args) == 1:
	self.message("%s = %s" % (args[0], self.aliases[args[0]]))
	else:
	self.aliases[args[0]] = ' '.join(args[1:])
	def do_unalias(self, arg):
	"""unalias name
	Delete the specified alias.
	"""
	args = arg.split()
	if len(args) == 0: return
	if args[0] in self.aliases:
	del self.aliases[args[0]]
	def complete_unalias(self, text, line, begidx, endidx):
	return [a for a in self.aliases if a.startswith(text)]
	# List of all the commands making the program resume execution.
	commands_resuming = ['do_continue', 'do_step', 'do_next', 'do_return',
	'do_quit', 'do_jump']
	# Print a traceback starting at the top stack frame.
	# The most recently entered frame is printed last;
	# this is different from dbx and gdb, but consistent with
	# the Python interpreter's stack trace.
	# It is also consistent with the up/down commands (which are
	# compatible with dbx and gdb: up moves towards 'main()'
	# and down moves towards the most recent stack frame).
	def print_stack_trace(self):
	try:
	for frame_lineno in self.stack:
	self.print_stack_entry(frame_lineno)
	except KeyboardInterrupt:
	pass
	def print_stack_entry(self, frame_lineno, prompt_prefix=line_prefix):
	frame, lineno = frame_lineno
	if frame is self.curframe:
	prefix = '> '
	else:
	prefix = ' '
	self.message(prefix +
	self.format_stack_entry(frame_lineno, prompt_prefix))
	# Provide help
	def do_help(self, arg):
	"""h(elp)
	Without argument, print the list of available commands.
	With a command name as argument, print help about that command.
	"help pdb" shows the full pdb documentation.
	"help exec" gives help on the ! command.
	"""
	if not arg:
	return cmd.Cmd.do_help(self, arg)
	try:
	try:
	topic = getattr(self, 'help_' + arg)
	return topic()
	except AttributeError:
	command = getattr(self, 'do_' + arg)
	except AttributeError:
	self.error('No help for %r' % arg)
	else:
	if sys.flags.optimize >= 2:
	self.error('No help for %r; please do not run Python with -OO '
	'if you need command help' % arg)
	return
	self.message(command.__doc__.rstrip())
	do_h = do_help
	def help_exec(self):
	"""(!) statement
	Execute the (one-line) statement in the context of the current
	stack frame. The exclamation point can be omitted unless the
	first word of the statement resembles a debugger command. To
	assign to a global variable you must always prefix the command
	with a 'global' command, e.g.:
	(Pdb) global list_options; list_options = ['-l']
	(Pdb)
	"""
	self.message((self.help_exec.__doc__ or '').strip())
	def help_pdb(self):
	help()
	# other helper functions
	def lookupmodule(self, filename):
	"""Helper function for break/clear parsing -- may be overridden.
	lookupmodule() translates (possibly incomplete) file or module name
	into an absolute file name.
	"""
	if os.path.isabs(filename) and os.path.exists(filename):
	return filename
	f = os.path.join(sys.path[0], filename)
	if os.path.exists(f) and self.canonic(f) == self.mainpyfile:
	return f
	root, ext = os.path.splitext(filename)
	if ext == '':
	filename = filename + '.py'
	if os.path.isabs(filename):
	return filename
	for dirname in sys.path:
	while os.path.islink(dirname):
	dirname = os.readlink(dirname)
	fullname = os.path.join(dirname, filename)
	if os.path.exists(fullname):
	return fullname
	return None
	def _runmodule(self, module_name):
	self._wait_for_mainpyfile = True
	self._user_requested_quit = False
	import runpy
	mod_name, mod_spec, code = runpy._get_module_details(module_name)
	self.mainpyfile = self.canonic(code.co_filename)
	import __main__
	__main__.__dict__.clear()
	__main__.__dict__.update({
	"__name__": "__main__",
	"__file__": self.mainpyfile,
	"__package__": mod_spec.parent,
	"__loader__": mod_spec.loader,
	"__spec__": mod_spec,
	"__builtins__": __builtins__,
	})
	self.run(code)
	def _runscript(self, filename):
	# The script has to run in __main__ namespace (or imports from
	# __main__ will break).
	#
	# So we clear up the __main__ and set several special variables
	# (this gets rid of pdb's globals and cleans old variables on restarts).
	import __main__
	__main__.__dict__.clear()
	__main__.__dict__.update({"__name__" : "__main__",
	"__file__" : filename,
	"__builtins__": __builtins__,
	})
	# When bdb sets tracing, a number of call and line events happens
	# BEFORE debugger even reaches user's code (and the exact sequence of
	# events depends on python version). So we take special measures to
	# avoid stopping before we reach the main script (see user_line and
	# user_call for details).
	self._wait_for_mainpyfile = True
	self.mainpyfile = self.canonic(filename)
	self._user_requested_quit = False
	with open(filename, "rb") as fp:
	statement = "exec(compile(%r, %r, 'exec'))" % \
	(fp.read(), self.mainpyfile)
	self.run(statement)
	# Collect all command help into docstring, if not run with -OO
	if __doc__ is not None:
	# unfortunately we can't guess this order from the class definition
	_help_order = [
	'help', 'where', 'down', 'up', 'break', 'tbreak', 'clear', 'disable',
	'enable', 'ignore', 'condition', 'commands', 'step', 'next', 'until',
	'jump', 'return', 'retval', 'run', 'continue', 'list', 'longlist',
	'args', 'p', 'pp', 'whatis', 'source', 'display', 'undisplay',
	'interact', 'alias', 'unalias', 'debug', 'quit',
	]
	for _command in _help_order:
	__doc__ += getattr(Pdb, 'do_' + _command).__doc__.strip() + '\n\n'
	__doc__ += Pdb.help_exec.__doc__
	del _help_order, _command
	# Simplified interface
	def run(statement, globals=None, locals=None):
	Pdb().run(statement, globals, locals)
	def runeval(expression, globals=None, locals=None):
	return Pdb().runeval(expression, globals, locals)
	def runctx(statement, globals, locals):
	# B/W compatibility
	run(statement, globals, locals)
	def runcall(*args, **kwds):
	return Pdb().runcall(*args, **kwds)
	def set_trace(*, header=None):
	pdb = Pdb()
	if header is not None:
	pdb.message(header)
	pdb.set_trace(sys._getframe().f_back)
	# Post-Mortem interface
	def post_mortem(t=None):
	# handling the default
	if t is None:
	# sys.exc_info() returns (type, value, traceback) if an exception is
	# being handled, otherwise it returns None
	t = sys.exc_info()[2]
	if t is None:
	raise ValueError("A valid traceback must be passed if no "
	"exception is being handled")
	p = Pdb()
	p.reset()
	p.interaction(None, t)
	def pm():
	post_mortem(sys.last_traceback)
	# Main program for testing
	TESTCMD = 'import x; x.main()'
	def test():
	run(TESTCMD)
	# print help
	def help():
	import pydoc
	pydoc.pager(__doc__)
	_usage = """\
	usage: pdb.py [-c command] ... [-m module | pyfile] [arg] ...
	Debug the Python program given by pyfile. Alternatively,
	an executable module or package to debug can be specified using
	the -m switch.
	Initial commands are read from .pdbrc files in your home directory
	and in the current directory, if they exist. Commands supplied with
	-c are executed after commands from .pdbrc files.
	To let the script run until an exception occurs, use "-c continue".
	To let the script run up to a given line X in the debugged file, use
	"-c 'until X'"."""
	def main():
	import getopt
	opts, args = getopt.getopt(sys.argv[1:], 'mhc:', ['--help', '--command='])
	if not args:
	print(_usage)
	sys.exit(2)
	commands = []
	run_as_module = False
	for opt, optarg in opts:
	if opt in ['-h', '--help']:
	print(_usage)
	sys.exit()
	elif opt in ['-c', '--command']:
	commands.append(optarg)
	elif opt in ['-m']:
	run_as_module = True
	mainpyfile = args[0] # Get script filename
	if not run_as_module and not os.path.exists(mainpyfile):
	print('Error:', mainpyfile, 'does not exist')
	sys.exit(1)
	sys.argv[:] = args # Hide "pdb.py" and pdb options from argument list
	# Replace pdb's dir with script's dir in front of module search path.
	if not run_as_module:
	sys.path[0] = os.path.dirname(mainpyfile)
	# Note on saving/restoring sys.argv: it's a good idea when sys.argv was
	# modified by the script being debugged. It's a bad idea when it was
	# changed by the user from the command line. There is a "restart" command
	# which allows explicit specification of command line arguments.
	pdb = Pdb()
	pdb.rcLines.extend(commands)
	while True:
	try:
	if run_as_module:
	pdb._runmodule(mainpyfile)
	else:
	pdb._runscript(mainpyfile)
	if pdb._user_requested_quit:
	break
	print("The program finished and will be restarted")
	except Restart:
	print("Restarting", mainpyfile, "with arguments:")
	print("\t" + " ".join(args))
	except SystemExit:
	# In most cases SystemExit does not warrant a post-mortem session.
	print("The program exited via sys.exit(). Exit status:", end=' ')
	print(sys.exc_info()[1])
	except SyntaxError:
	traceback.print_exc()
	sys.exit(1)
	except:
	traceback.print_exc()
	print("Uncaught exception. Entering post mortem debugging")
	print("Running 'cont' or 'step' will restart the program")
	t = sys.exc_info()[2]
	pdb.interaction(None, t)
	print("Post mortem debugger finished. The " + mainpyfile +
	" will be restarted")
	# When invoked as main program, invoke the debugger on a script
	if __name__ == '__main__':
	import pdb
	pdb.main()