mlxtend version: 0.23.1


Counter(stderr=False, start_newline=True, precision=0, name=None)

Class to display the progress of for-loop iterators.


  • stderr : bool (default: True)

    Prints output to sys.stderr if True; uses sys.stdout otherwise.

  • start_newline : bool (default: True)

    Prepends a new line to the counter, which prevents overwriting counters if multiple counters are printed in succession. precision: int (default: 0) Sets the number of decimal places when displaying the time elapsed in seconds.

  • name : string (default: None)

    Prepends the specified name before the counter to allow distinguishing between multiple counters.


  • curr_iter : int

    The current iteration.

  • start_time : float

    The system's time in seconds when the Counter was initialized.

  • end_time : float

    The system's time in seconds when the Counter was last updated.


    >>> cnt = Counter()
    >>> for i in range(20):
    ...     # do some computation
    ...     time.sleep(0.1)
    ...     cnt.update()
    20 iter | 2 sec
    >>> print('The counter was initialized.'
    ' %d seconds ago.' % (time.time() - cnt.start_time))
    The counter was initialized 2 seconds ago
    >>> print('The counter was last updated'
    ' %d seconds ago.' % (time.time() - cnt.end_time))
    The counter was last updated 0 seconds ago.

    For more usage examples, please see



Print current iteration and time elapsed.


assert_raises(exception_type, message, func, args, *kwargs)

Check that an exception is raised with a specific message


  • exception_type : exception

    The exception that should be raised

  • message : str (default: None)

    The error message that should be raised. Ignored if False or None.

  • func : callable

    The function that raises the exception

  • *args : positional arguments to func.

  • **kwargs : keyword arguments to func


check_Xy(X, y, y_int=True)



format_kwarg_dictionaries(default_kwargs=None, user_kwargs=None, protected_keys=None)

Function to combine default and user specified kwargs dictionaries


  • default_kwargs : dict, optional

    Default kwargs (default is None).

  • user_kwargs : dict, optional

    User specified kwargs (default is None).

  • protected_keys : array_like, optional

    Sequence of keys to be removed from the returned dictionary (default is None).


  • formatted_kwargs : dict

    Formatted kwargs dictionary.