Doc/lib/libconsts.tex

   1 \section{Built-in Constants}
   2
   3 A small number of constants live in the built-in namespace.  They are:
   4
   5 \begin{datadesc}{False}
   6   The false value of the \class{bool} type.
   7   \versionadded{2.3}
   8 \end{datadesc}
   9
  10 \begin{datadesc}{True}
  11   The true value of the \class{bool} type.
  12   \versionadded{2.3}
  13 \end{datadesc}
  14
  15 \begin{datadesc}{None}
  16   The sole value of \code{\refmodule{types}.NoneType}.  \code{None} is
  17   frequently used to represent the absence of a value, as when default
  18   arguments are not passed to a function.
  19 \end{datadesc}
  20
  21 \begin{datadesc}{NotImplemented}
  22   Special value which can be returned by the ``rich comparison''
  23   special methods (\method{__eq__()}, \method{__lt__()}, and friends),
  24   to indicate that the comparison is not implemented with respect to
  25   the other type.
  26 \end{datadesc}
  27
  28 \begin{datadesc}{Ellipsis}
  29   Special value used in conjunction with extended slicing syntax.
  30   % XXX Someone who understands extended slicing should fill in here.
  31 \end{datadesc}