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Python: Statements

When we're making a dish, we follow the recipe carefully. Otherwise, the food won't turn out as expected. The same rule applies to programming.

If you want to see the expected result onscreen, the computer needs to have clear, step-by-step directions. This can be done using instructions. An instruction is a command to the computer, a unit of execution. Python code in this case is a set of instructions. It can be presented as a step-by-step recipe.

Python code is run by an interpreter, a program that executes instructions strictly, line by line. Like the steps in a recipe, the instructions for the interpreter are written in order and are separated from each other by skipping to the next line.

Developers must understand the order of operations in the code, and be able to mentally divide the program into independent parts that are convenient for analysis.

Let's look at an example of some code with two instructions. When it's started, two sentences are displayed sequentially on the screen:

print('Mother of Dragons.')
print('Dracarys!')
# => Mother of Dragons.
# => Dracarys!

We said above that instructions are separated from each other by a line break. But there is another way; they can be separated by a semicolon — ;:

print('Mother of Dragons.'); print('Drakarys!')

There is no technical difference between the first and second version; the interpreter will understand the instructions the same way. The only difference is that it's inconvenient, physically, to read the second version.

It's better to place the instructions under each other. This makes it easier for colleagues to read your code, maintain it, and make changes.

Instructions

Display three names, one after another: Robert, Stannis, Renly. The result should be that the following is shown on the screen:

Robert
Stannis
Renly

For each name, use Python's own print() call.

The exercise doesn't pass checking. What to do? 😶

If you've reached a deadlock it's time to ask your question in the «Discussions». How ask a question correctly:

  • Be sure to attach the test output, without it it's almost impossible to figure out what went wrong, even if you show your code. It's complicated for developers to execute code in their heads, but having a mistake before their eyes most probably will be helpful.
In my environment the code works, but not here 🤨

Tests are designed so that they test the solution in different ways and against different data. Often the solution works with one kind of input data but doesn't work with others. Check the «Tests» tab to figure this out, you can find hints at the error output.

My code is different from the teacher's one 🤔

It's fine. 🙆 One task in programming can be solved in many different ways. If your code passed all tests, it complies with the task conditions.

In some rare cases, the solution may be adjusted to the tests, but this can be seen immediately.

I've read the lessons but nothing is clear 🙄

It's hard to make educational materials that will suit everyone. We do our best but there is always something to improve. If you see a material that is not clear to you, describe the problem in “Discussions”. It will be great if you'll write unclear points in the question form. Usually, we need a few days for corrections.

By the way, you can participate in courses improvement. There is a link below to the lessons course code which you can edit right in your browser.

Tips

Definitions

  • Interpreter a program that runs code in Python.

  • Statement a command for the computer written in a programming language. Python code is a set of instructions, most often separated by a line break.