Convert tabs, newlines and/or spaces to visible characters.
Options accepted:
`spaces` : string or bool
If this is a one-character string, spaces will be replaces by this string.
If it is another true value, spaces will be replaced by ``·`` (unicode
MIDDLE DOT). If it is a false value, spaces will not be replaced. The
default is ``False``.
`tabs` : string or bool
The same as for `spaces`, but the default replacement character is ``»``
(unicode RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK). The default value
is ``False``. Note: this will not work if the `tabsize` option for the
lexer is nonzero, as tabs will already have been expanded then.
`tabsize` : int
If tabs are to be replaced by this filter (see the `tabs` option), this
is the total number of characters that a tab should be expanded to.
The default is ``8``.
`newlines` : string or bool
The same as for `spaces`, but the default replacement character is ``¶``
(unicode PILCROW SIGN). The default value is ``False``.
`wstokentype` : bool
If true, give whitespace the special `Whitespace` token type. This allows
styling the visible whitespace differently (e.g. greyed out), but it can
disrupt background colors. The default is ``True``.
.. versionadded:: 0.8