This property method takes the non-empty string self.__expr, an arithmetic expression in infix notation, calls _getPostfix(expr) to obtain the postfix expression of self.__expr and then uses a Stack (as described in the Stack video lecture from Module 5) to evaluate the obtained postfix expression. All values returned by calculator should be float if expr is a correct expression, otherwise it must return None. - Do not use exec or eval function. You will not receive credit if your program uses any of the two functions anywhere - Note that you can write the code for this method without having an implementation for _getPostfix. The process for calculate is explained during the stack video lectures

This first part of the film shows the early history of motion pictures. how accurate do you think the portrayal of the early motion picture industry is? why? is historical accuracy important in films and theatre productions? explain. in the scene where don is going to the party (starting at time code 14: 51), we see a street scene as he first rides with cosmo and then with kathy. what aspects did the filmmaker include to make the scene look and feel like don, cosmo, and kathy are riding in a car on a street? think about elements such as scenery, sound, props, lighting, and so on. a "talkie" picture is shown starting around time code 21: 15. how does the audience in the film react to the "talkie"? what influence do audiences have on film and theatre performances? how do film and theatre actors influence audiences? in the musical scene with cosmo (starting at time code 27: 00), how does the actor use props? what is the result? do you think the use of props effectively fulfilled the artistic vision for this musical number? why or why not?

Which of the following “invisible” marks represents an inserted tab?

Octothorpe is another name for what common computer keyboard symbol?