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Input, Variables, and Enumeration Related Tips

Input, Variables, and Enumeration Related Tips

Learn how to prompt input, use dummy variables, and enum in this lesson.

Let input() speak for itself

There are many questions we must ask when a console-based program suddenly stops. Why? Did it hang up? Is it busy? Is it waiting for the input? If so, for what is it waiting? As a programmer, we can eliminate most of these questions by providing prompts.

A prompt is a printed invitation to enter some missing information. We should display a prompt just before the program stops and wait for user input (presumably by calling the input() function). The prompt should explain concisely, in a language suitable to the expected user, what the user should input and how. It is customary, but not required, for a prompt to end with a colon and space.

We can use the print() function to display the prompt, followed by input() to collect the input. A better solution is to let input() speak for itself; if we pass an argument to input(), the argument will be printed just before the function stops:

year = input('Enter year of birth: ')

Keeping the prompt and the collector together self-documents the collector’s purpose and reminds the user of which input is expected, especially if the program requires more than one input.

Remember that the prompt is merely a string. It can be a constant and can be pre-calculated. It can also be calculated during the call to personalize the invitation or configure it in any other way: ...

name = input('Enter