Source code for colour.utilities.common

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
Common Utilities
================

Defines common utilities objects that don"t fall in any specific category.
"""

from __future__ import division, unicode_literals

__author__ = 'Colour Developers'
__copyright__ = 'Copyright (C) 2013 - 2015 - Colour Developers'
__license__ = 'New BSD License - http://opensource.org/licenses/BSD-3-Clause'
__maintainer__ = 'Colour Developers'
__email__ = 'colour-science@googlegroups.com'
__status__ = 'Production'

__all__ = ['batch',
           'is_scipy_installed',
           'is_string']


[docs]def batch(iterable, k=3):
    """
    Returns a batch generator from given iterable.

    Parameters
    ----------
    iterable : iterable
        Iterable to create batches from.
    k : integer
        Batches size.

    Returns
    -------
    bool
        Is *string_like* variable.

    Examples
    --------
    >>> batch(tuple(range(10)))  # doctest: +ELLIPSIS
    <generator object batch at 0x...>
    """

    for i in range(0, len(iterable), k):
        yield iterable[i:i + k]


[docs]def is_scipy_installed(raise_exception=False):
    """
    Returns if *scipy* is installed and available.

    Parameters
    ----------
    raise_exception : bool
        Raise exception if *scipy* is unavailable.

    Returns
    -------
    bool
        Is *scipy* installed.

    Raises
    ------
    ImportError
        If *scipy* is not installed.
    """

    try:
        # Importing *scipy* Api features used in *Colour*.
        import scipy.interpolate
        import scipy.ndimage
        import scipy.spatial

        return True
    except ImportError as error:
        if raise_exception:
            raise ImportError(('"scipy" or specific "scipy" Api features '
                               'are not available: "{1}".').format(error))
        return False


[docs]def is_string(data):
    """
    Returns if given data is a *string_like* variable.

    Parameters
    ----------
    data : object
        Data to test.

    Returns
    -------
    bool
        Is *string_like* variable.

    Examples
    --------
    >>> is_string('I`m a string!')
    True
    >>> is_string(['I`m a string!'])
    False
    """

    return True if isinstance(data, basestring) else False