Abs

    """Return a sympy object representing the absolute value of the argument.

    This is an extension of the built-in function abs() to accept symbolic
    values. If you pass a SymPy expression to the built-in abs(), it will
    pass it automatically to Abs().

    Examples::

        >>> from sympy import Abs, Symbol, S
        >>> x = Symbol('x', real=True)
        >>> Abs(-x)
        Abs(x)
        >>> Abs(x**2)
        x**2
        >>> Abs(-1)
        1
        >>> type(_)
        <class 'sympy.core.numbers.One'>

        The Python built-in will return either an Expr or int depending
        on the type of argument::

        >>> type(abs(1)) # arg is int
        <type 'int'>
        >>> abs(-x) # arg is a sympy exprssion
        Abs(x)

    """