The Python Language Reference, Release 3.9.5 a class instance: The class must define a __call__() method; the effect is then the same as if that method was called. a class instance method: The corresponding user-defined function is called, with an argument list that is one longer than the argument list of the call: the instance becomes the first argument. a class object: A new instance of that class is returned. 6.4 Await expression Suspend the execution of coroutine on an awaitable object. Can only be used inside a coroutine function . await_expr ::= "await" primary New in version 3.5. The power operator binds more tightly than unary operators on its left; it binds less tightly than unary operators on its right. The syntax is: power ::= ( await_expr | primary ) ["**" u_expr ] Thus, in an unparenthesized sequence of power and unary operators, the operators are evaluated from right to left (this does not constrain the evaluation order for the operands):$_{-1**2}$ results in$_{-1}$ . The power operator has the same semantics as the built-in$_{pow()}$ function, when called with two arguments: it yields its left argument raised to the power of its right argument. The numeric arguments are first converted to a common type, and the result is of that type. 6.5 The power operator For int operands, the result has the same type as the operands unless the second argument is negative; in that case, all arguments are converted to float and a float result is delivered. For example,$_{10**2}$ returns$_{100}$ , but$_{10**-2}$ returns$_{0.01}$ . Raising$_{0.0}$ to a negative power results in a$_{ZeroDivisionError}$ . Raising a negative number to a fractional power results in a$_{complex}$ number. (In earlier versions it raised a$_{ValueError}$.) All unary arithmetic and bitwise operations have the same priority: u_expr ::= power | "-" u_expr | "+" u_expr | "~" u_expr The unary$_{+}$(plus) operator yields its numeric argument unchanged. The unary$_{-}$(minus) operator yields the negation of its numeric argument. The unary$_{~}$ (invert) operator yields the bitwise inversion of its integer argument. The bitwise inversion of$_{x}$is defined as$_{-(x+1)}$ . It only applies to integral numbers. In all three cases, if the argument does not have the proper type, a$_{TypeError}$ exception is raised. Chapter 6. Expressions 74 6.6 Unary arithmetic and bitwise operations