Python sys.tracebacklimit() Examples

def extract_tb(tb, limit=None):
    """This implementation is stolen from traceback module but respects __traceback_hide__."""
    if limit is None:
        if hasattr(sys, "tracebacklimit"):
            limit = sys.tracebacklimit
    tb_list = []
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        if not _should_skip_frame(f):
            lineno = tb.tb_lineno
            co = f.f_code
            filename = co.co_filename
            name = co.co_name
            linecache.checkcache(filename)
            line = linecache.getline(filename, lineno, f.f_globals)
            if line:
                line = line.strip()
            else:
                line = None
            tb_list.append((filename, lineno, name, line))
        tb = tb.tb_next
        n = n + 1
    return tb_list 

def main():
    sys.tracebacklimit = 0

    args = get_args()

    if args.quoting_mode == 'minimal':
        args.quoting = csv.QUOTE_MINIMAL
    elif args.quoting_mode == 'all':
        args.quoting = csv.QUOTE_ALL
    elif args.quoting_mode == 'non-numeric':
        args.quoting = csv.QUOTE_NONNUMERIC
    elif args.quoting_mode == 'none':
        args.quoting = csv.QUOTE_NONE

    if os.path.isdir(args.input):
        process_directory(args.input, args.output, args)
    elif os.path.isfile(args.input):
        process_file(args.input, args.output, args) 

def check_unsupported_blender_versions():
    # Don't allow Blender versions older than 2.79
    if bpy.app.version < (2, 79):
        unregister()
        sys.tracebacklimit = 0
        raise ImportError('\n\nBlender versions older than 2.79 are not supported by Cats. '
                          '\nPlease use Blender 2.79 or later.'
                          '\n')

    # Versions 2.80.0 to 2.80.74 are beta versions, stable is 2.80.75
    if (2, 80, 0) <= bpy.app.version < (2, 80, 75):
        unregister()
        sys.tracebacklimit = 0
        raise ImportError('\n\nYou are still on the beta version of Blender 2.80!'
                          '\nPlease update to the release version of Blender 2.80.'
                          '\n') 

def getLimit(self):
        limit = self.limit
        if limit is None:
            limit = getattr(sys, 'tracebacklimit', None)
        return limit 

def print_tb(tb, limit=None, file=None):
    """Print up to 'limit' stack trace entries from the traceback 'tb'.

    If 'limit' is omitted or None, all entries are printed.  If 'file'
    is omitted or None, the output goes to sys.stderr; otherwise
    'file' should be an open file or file-like object with a write()
    method.
    """
    if file is None:
        file = sys.stderr
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        _print(file,
               '  File "%s", line %d, in %s' % (filename, lineno, name))
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: _print(file, '    ' + line.strip())
        tb = tb.tb_next
        n = n+1 

def simpleException(self, exception, msg):
        self._solveDepthCnt = 0
        sys.tracebacklimit = 0
        raise exception(msg)

    # ------------------------------------------------------------------------------- #
    # debug the request via the response
    # ------------------------------------------------------------------------------- # 

def print_tb(tb, limit=None, file=None):
    """Print up to 'limit' stack trace entries from the traceback 'tb'.

    If 'limit' is omitted or None, all entries are printed.  If 'file'
    is omitted or None, the output goes to sys.stderr; otherwise
    'file' should be an open file or file-like object with a write()
    method.
    """
    if file is None:
        file = sys.stderr
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        _print(file,
               '  File "%s", line %d, in %s' % (filename, lineno, name))
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: _print(file, '    ' + line.strip())
        tb = tb.tb_next
        n = n+1 

def extract_stack(f=None, limit = None):
    """Extract the raw traceback from the current stack frame.

    The return value has the same format as for extract_tb().  The
    optional 'f' and 'limit' arguments have the same meaning as for
    print_stack().  Each item in the list is a quadruple (filename,
    line number, function name, text), and the entries are in order
    from oldest to newest stack frame.
    """
    if f is None:
        try:
            raise ZeroDivisionError
        except ZeroDivisionError:
            f = sys.exc_info()[2].tb_frame.f_back
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while f is not None and (limit is None or n < limit):
        lineno = f.f_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: line = line.strip()
        else: line = None
        list.append((filename, lineno, name, line))
        f = f.f_back
        n = n+1
    list.reverse()
    return list 

def extract_tb(tb, limit = None):
    """Return list of up to limit pre-processed entries from traceback.

    This is useful for alternate formatting of stack traces.  If
    'limit' is omitted or None, all entries are extracted.  A
    pre-processed stack trace entry is a quadruple (filename, line
    number, function name, text) representing the information that is
    usually printed for a stack trace.  The text is a string with
    leading and trailing whitespace stripped; if the source is not
    available it is None.
    """
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: line = line.strip()
        else: line = None
        list.append((filename, lineno, name, line))
        tb = tb.tb_next
        n = n+1
    return list 

def extract_tb(tb, limit = None):
    """Return list of up to limit pre-processed entries from traceback.

    This is useful for alternate formatting of stack traces.  If
    'limit' is omitted or None, all entries are extracted.  A
    pre-processed stack trace entry is a quadruple (filename, line
    number, function name, text) representing the information that is
    usually printed for a stack trace.  The text is a string with
    leading and trailing whitespace stripped; if the source is not
    available it is None.
    """
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: line = line.strip()
        else: line = None
        list.append((filename, lineno, name, line))
        tb = tb.tb_next
        n = n+1
    return list 

def print_tb(tb, limit=None, file=None):
    """Print up to 'limit' stack trace entries from the traceback 'tb'.

    If 'limit' is omitted or None, all entries are printed.  If 'file'
    is omitted or None, the output goes to sys.stderr; otherwise
    'file' should be an open file or file-like object with a write()
    method.
    """
    if file is None:
        file = sys.stderr
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        _print(file,
               '  File "%s", line %d, in %s' % (filename, lineno, name))
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: _print(file, '    ' + line.strip())
        tb = tb.tb_next
        n = n+1 

def extract_tb(tb, limit = None):
    """Return list of up to limit pre-processed entries from traceback.

    This is useful for alternate formatting of stack traces.  If
    'limit' is omitted or None, all entries are extracted.  A
    pre-processed stack trace entry is a quadruple (filename, line
    number, function name, text) representing the information that is
    usually printed for a stack trace.  The text is a string with
    leading and trailing whitespace stripped; if the source is not
    available it is None.
    """
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: line = line.strip()
        else: line = None
        list.append((filename, lineno, name, line))
        tb = tb.tb_next
        n = n+1
    return list 

def extract_tb(tb, limit = None):
    """Return list of up to limit pre-processed entries from traceback.

    This is useful for alternate formatting of stack traces.  If
    'limit' is omitted or None, all entries are extracted.  A
    pre-processed stack trace entry is a quadruple (filename, line
    number, function name, text) representing the information that is
    usually printed for a stack trace.  The text is a string with
    leading and trailing whitespace stripped; if the source is not
    available it is None.
    """
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: line = line.strip()
        else: line = None
        list.append((filename, lineno, name, line))
        tb = tb.tb_next
        n = n+1
    return list 

def print_tb(tb, limit=None, file=None):
    """Print up to 'limit' stack trace entries from the traceback 'tb'.

    If 'limit' is omitted or None, all entries are printed.  If 'file'
    is omitted or None, the output goes to sys.stderr; otherwise
    'file' should be an open file or file-like object with a write()
    method.
    """
    if file is None:
        file = sys.stderr
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        _print(file,
               '  File "%s", line %d, in %s' % (filename, lineno, name))
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: _print(file, '    ' + line.strip())
        tb = tb.tb_next
        n = n+1 

def extract_stack(f=None, limit = None):
    """Extract the raw traceback from the current stack frame.

    The return value has the same format as for extract_tb().  The
    optional 'f' and 'limit' arguments have the same meaning as for
    print_stack().  Each item in the list is a quadruple (filename,
    line number, function name, text), and the entries are in order
    from oldest to newest stack frame.
    """
    if f is None:
        try:
            raise ZeroDivisionError
        except ZeroDivisionError:
            f = sys.exc_info()[2].tb_frame.f_back
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while f is not None and (limit is None or n < limit):
        lineno = f.f_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: line = line.strip()
        else: line = None
        list.append((filename, lineno, name, line))
        f = f.f_back
        n = n+1
    list.reverse()
    return list 

def extract_tb(tb, limit = None):
    """Return list of up to limit pre-processed entries from traceback.

    This is useful for alternate formatting of stack traces.  If
    'limit' is omitted or None, all entries are extracted.  A
    pre-processed stack trace entry is a quadruple (filename, line
    number, function name, text) representing the information that is
    usually printed for a stack trace.  The text is a string with
    leading and trailing whitespace stripped; if the source is not
    available it is None.
    """
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: line = line.strip()
        else: line = None
        list.append((filename, lineno, name, line))
        tb = tb.tb_next
        n = n+1
    return list 

def print_tb(tb, limit=None, file=None):
    """Print up to 'limit' stack trace entries from the traceback 'tb'.

    If 'limit' is omitted or None, all entries are printed.  If 'file'
    is omitted or None, the output goes to sys.stderr; otherwise
    'file' should be an open file or file-like object with a write()
    method.
    """
    if file is None:
        file = sys.stderr
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        _print(file,
               '  File "%s", line %d, in %s' % (filename, lineno, name))
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: _print(file, '    ' + line.strip())
        tb = tb.tb_next
        n = n+1 

def extract_stack(f=None, limit=None):
    """Extract the raw traceback from the current stack frame.

    The return value has the same format as for extract_tb().  The
    optional 'f' and 'limit' arguments have the same meaning as for
    print_stack().  Each item in the list is a quadruple (filename,
    line number, function name, text), and the entries are in order
    from oldest to newest stack frame.
    """
    if f is None:
        try:
            raise ZeroDivisionError
        except ZeroDivisionError:
            f = sys.exc_info()[2].tb_frame.f_back
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while f is not None and (limit is None or n < limit):
        lineno = f.f_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line:
            line = line.strip()
        else:
            line = None
        list.append((filename, lineno, name, line))
        f = f.f_back
        n = n+1
    list.reverse()
    return list 

def extract_tb(tb, limit=None):
    """Return list of up to limit pre-processed entries from traceback.

    This is useful for alternate formatting of stack traces.  If
    'limit' is omitted or None, all entries are extracted.  A
    pre-processed stack trace entry is a quadruple (filename, line
    number, function name, text) representing the information that is
    usually printed for a stack trace.  The text is a string with
    leading and trailing whitespace stripped; if the source is not
    available it is None.
    """
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line:
            line = line.strip()
        else:
            line = None
        list.append((filename, lineno, name, line))
        tb = tb.tb_next
        n = n+1
    return list 

def print_tb(tb, limit=None, file=None):
    """Print up to 'limit' stack trace entries from the traceback 'tb'.

    If 'limit' is omitted or None, all entries are printed.  If 'file'
    is omitted or None, the output goes to sys.stderr; otherwise
    'file' should be an open file or file-like object with a write()
    method.
    """
    if file is None:
        file = sys.stderr
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        _print(file, '  File "%s", line %d, in %s' % (filename, lineno, name))
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line:
            _print(file, '    ' + line.strip())
        tb = tb.tb_next
        n = n+1 

def __init__(self, uri=False):
        self.user = None
        self.ip = None
        self.port = None
        self.members = []
        self.hosts = []
        self.version = None
        self.w_hostgroup = 2
        self.b_w_hostgroup = 4
        self.r_hostgroup = 3
        self.o_hostgroup = 1
        self.max_writer = 1
        self.writer_is_reader = 0
        self.max_transaction_behind = 100
        self.monitor_user = "monitor"
        self.monitor_pwd = "monitor"
        self.uri = uri

        self.user = shell.parse_uri(self.uri)['user']
        if self.user == 'admin':
           sys.tracebacklimit = 0
           raise Exception("You should not use the default 'admin' user, please create a new one in ProxySQL")
        self.ip = shell.parse_uri(self.uri)['host']
        self.port = shell.parse_uri(self.uri)['port']
        if not "password" in shell.parse_uri(self.uri):
            self.__password = shell.prompt('Password: ',{'type': 'password'})
        else:
            self.__password = shell.parse_uri(self.uri)['password']
        try:
            self.session = mysql.get_session("%s:%s@%s:%s?ssl-mode=DISABLED" % (self.user, self.__password, self.ip, self.port))
            stmt = "select version()"
            result = self.session.run_sql(stmt)
            self.version = result.fetch_one()[0]
            print("Connected to ProxySQL (%s)" % self.version)
        except:
            sys.tracebacklimit = 0
            raise Exception("Not possible to connect to ProxySQL admin interface !") 

def init_logger():
        logger = logging.getLogger(__name__)
        logger.setLevel(level=PYJFUZZ_LOGLEVEL)
        filehandler = logging.FileHandler("pjf_{0}.log".format(time.strftime("%d_%m_%Y")))
        logger.addHandler(filehandler)
        sys.tracebacklimit = 10
        return logger 

def extract_stack(f=None, limit = None):
    """Extract the raw traceback from the current stack frame.

    The return value has the same format as for extract_tb().  The
    optional 'f' and 'limit' arguments have the same meaning as for
    print_stack().  Each item in the list is a quadruple (filename,
    line number, function name, text), and the entries are in order
    from oldest to newest stack frame.
    """
    if f is None:
        try:
            raise ZeroDivisionError
        except ZeroDivisionError:
            f = sys.exc_info()[2].tb_frame.f_back
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while f is not None and (limit is None or n < limit):
        lineno = f.f_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: line = line.strip()
        else: line = None
        list.append((filename, lineno, name, line))
        f = f.f_back
        n = n+1
    list.reverse()
    return list 

def extract_tb(tb, limit = None):
    """Return list of up to limit pre-processed entries from traceback.

    This is useful for alternate formatting of stack traces.  If
    'limit' is omitted or None, all entries are extracted.  A
    pre-processed stack trace entry is a quadruple (filename, line
    number, function name, text) representing the information that is
    usually printed for a stack trace.  The text is a string with
    leading and trailing whitespace stripped; if the source is not
    available it is None.
    """
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: line = line.strip()
        else: line = None
        list.append((filename, lineno, name, line))
        tb = tb.tb_next
        n = n+1
    return list 

def print_tb(tb, limit=None, file=None):
    """Print up to 'limit' stack trace entries from the traceback 'tb'.

    If 'limit' is omitted or None, all entries are printed.  If 'file'
    is omitted or None, the output goes to sys.stderr; otherwise
    'file' should be an open file or file-like object with a write()
    method.
    """
    if file is None:
        file = sys.stderr
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    n = 0
    while tb is not None and (limit is None or n < limit):
        f = tb.tb_frame
        lineno = tb.tb_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        _print(file,
               '  File "%s", line %d, in %s' % (filename,lineno,name))
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: _print(file, '    ' + line.strip())
        tb = tb.tb_next
        n = n+1 

def test_format_exception(self):
        try:
            self.last_raises5()
        except Exception:
            exc_type, exc_value, tb = sys.exc_info()
        # [1:-1] to exclude "Traceback (...)" header and
        # exception type and value
        def extract(**kwargs):
            return traceback.format_exception(exc_type, exc_value, tb, **kwargs)[1:-1]

        with support.swap_attr(sys, 'tracebacklimit', 1000):
            nolim = extract()
            self.assertEqual(len(nolim), 5+1)
            self.assertEqual(extract(limit=2), nolim[:2])
            self.assertEqual(extract(limit=10), nolim)
            self.assertEqual(extract(limit=-2), nolim[-2:])
            self.assertEqual(extract(limit=-10), nolim)
            self.assertEqual(extract(limit=0), [])
            del sys.tracebacklimit
            self.assertEqual(extract(), nolim)
            sys.tracebacklimit = 2
            self.assertEqual(extract(), nolim[:2])
            self.assertEqual(extract(limit=3), nolim[:3])
            self.assertEqual(extract(limit=-3), nolim[-3:])
            sys.tracebacklimit = 0
            self.assertEqual(extract(), [])
            sys.tracebacklimit = -1
            self.assertEqual(extract(), []) 

def test_extract_tb(self):
        try:
            self.last_raises5()
        except Exception:
            exc_type, exc_value, tb = sys.exc_info()
        def extract(**kwargs):
            return traceback.extract_tb(tb, **kwargs)

        with support.swap_attr(sys, 'tracebacklimit', 1000):
            nolim = extract()
            self.assertEqual(len(nolim), 5+1)
            self.assertEqual(extract(limit=2), nolim[:2])
            self.assertEqual(extract(limit=10), nolim)
            self.assertEqual(extract(limit=-2), nolim[-2:])
            self.assertEqual(extract(limit=-10), nolim)
            self.assertEqual(extract(limit=0), [])
            del sys.tracebacklimit
            self.assertEqual(extract(), nolim)
            sys.tracebacklimit = 2
            self.assertEqual(extract(), nolim[:2])
            self.assertEqual(extract(limit=3), nolim[:3])
            self.assertEqual(extract(limit=-3), nolim[-3:])
            sys.tracebacklimit = 0
            self.assertEqual(extract(), [])
            sys.tracebacklimit = -1
            self.assertEqual(extract(), []) 

def test_extract_stack(self):
        frame = self.last_returns_frame5()
        def extract(**kwargs):
            return traceback.extract_stack(frame, **kwargs)
        def assertEqualExcept(actual, expected, ignore):
            self.assertEqual(actual[:ignore], expected[:ignore])
            self.assertEqual(actual[ignore+1:], expected[ignore+1:])
            self.assertEqual(len(actual), len(expected))

        with support.swap_attr(sys, 'tracebacklimit', 1000):
            nolim = extract()
            self.assertGreater(len(nolim), 5)
            self.assertEqual(extract(limit=2), nolim[-2:])
            assertEqualExcept(extract(limit=100), nolim[-100:], -5-1)
            self.assertEqual(extract(limit=-2), nolim[:2])
            assertEqualExcept(extract(limit=-100), nolim[:100], len(nolim)-5-1)
            self.assertEqual(extract(limit=0), [])
            del sys.tracebacklimit
            assertEqualExcept(extract(), nolim, -5-1)
            sys.tracebacklimit = 2
            self.assertEqual(extract(), nolim[-2:])
            self.assertEqual(extract(limit=3), nolim[-3:])
            self.assertEqual(extract(limit=-3), nolim[:3])
            sys.tracebacklimit = 0
            self.assertEqual(extract(), [])
            sys.tracebacklimit = -1
            self.assertEqual(extract(), []) 

def eval(self, body, domain):
        try:
            js = 'var atob = function(str) {return Buffer.from(str, "base64").toString("binary");};' \
                 'var challenge = atob("%s");' \
                 'var context = {atob: atob};' \
                 'var options = {filename: "iuam-challenge.js", timeout: 4000};' \
                 'var answer = require("vm").runInNewContext(challenge, context, options);' \
                 'process.stdout.write(String(answer));' \
                 % base64.b64encode(template(body, domain).encode('UTF-8')).decode('ascii')

            return subprocess.check_output(['node', '-e', js])

        except OSError as e:
            if e.errno == 2:
                raise EnvironmentError(
                    'Missing Node.js runtime. Node is required and must be in the PATH (check with `node -v`).\n\n'
                    'Your Node binary may be called `nodejs` rather than `node`, '
                    'in which case you may need to run `apt-get install nodejs-legacy` on some Debian-based systems.\n\n'
                    '(Please read the cloudscraper README\'s Dependencies section: '
                    'https://github.com/VeNoMouS/cloudscraper#dependencies.)'
                )
            raise
        except Exception:
            sys.tracebacklimit = 0
            raise RuntimeError('Error executing Cloudflare IUAM Javascript in nodejs')


# ------------------------------------------------------------------------------- # 

def _raiseException(prefix, msg):
    sys.tracebacklimit = None
    raise(Exception('[OSMPythonTools.' + prefix + '] ' + msg))