environment/lib/python2.7/site-packages/IPython/utils/text.py
def qw(words,flat=0,sep=None,maxsplit=-1):
    """Similar to Perl's qw() operator, but with some more options.

    qw(words,flat=0,sep=' ',maxsplit=-1) -> words.split(sep,maxsplit)

    words can also be a list itself, and with flat=1, the output will be
    recursively flattened.

    Examples:

    >>> qw('1 2')
    ['1', '2']

    >>> qw(['a b','1 2',['m n','p q']])
    [['a', 'b'], ['1', '2'], [['m', 'n'], ['p', 'q']]]

    >>> qw(['a b','1 2',['m n','p q']],flat=1)
    ['a', 'b', '1', '2', 'm', 'n', 'p', 'q']
    """

    if isinstance(words, basestring):
        return [word.strip() for word in words.split(sep,maxsplit)
                if word and not word.isspace() ]
    if flat:
        return flatten(map(qw,words,[1]*len(words)))
    return map(qw,words)
def qw(words,flat=0,sep=None,maxsplit=-1):
    """Similar to Perl's qw() operator, but with some more options.

    qw(words,flat=0,sep=' ',maxsplit=-1) -> words.split(sep,maxsplit)

    words can also be a list itself, and with flat=1, the output will be
    recursively flattened.

    Examples:

    >>> qw('1 2')
    ['1', '2']

    >>> qw(['a b','1 2',['m n','p q']])
    [['a', 'b'], ['1', '2'], [['m', 'n'], ['p', 'q']]]

    >>> qw(['a b','1 2',['m n','p q']],flat=1)
    ['a', 'b', '1', '2', 'm', 'n', 'p', 'q']
    """

    if isinstance(words, basestring):
        return [word.strip() for word in words.split(sep,maxsplit)
                if word and not word.isspace() ]
    if flat:
        return flatten(map(qw,words,[1]*len(words)))
    return map(qw,words)
Similar to Perl's qw() operator, but with some more options.

    qw(words,flat=0,sep=' ',maxsplit=-1) -> words.split(sep,maxsplit)

    words can also be a list itself, and with flat=1, the output will be
    recursively flattened.

    Examples:

    >>> qw('1 2')
    ['1', '2']

    >>> qw(['a b','1 2',['m n','p q']])
    [['a', 'b'], ['1', '2'], [['m', 'n'], ['p', 'q']]]

    >>> qw(['a b','1 2',['m n','p q']],flat=1)
    ['a', 'b', '1', '2', 'm', 'n', 'p', 'q']