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Python: Immutability

Imagine we have this call:

name = 'Tirion'
print(name.upper())  # => TIRION
# What will this call print on the screen?
print(name)  # => ?

Calling the .upper() method returns a new value with all letters converted to upper case, but it does not change the original string. So inside the variable will be the old value: 'Tyrion'. This logic holds true for methods of all primitive types.

Instead of changing the value, you can replace it. This requires variables:

name = 'Tirion'
name = name.upper()
print(name)  # => TIRION


User input data often contains extra spaces at the end or beginning of a string. They're usually cut out using a method .strip(), for example, it was hello\n' and now it's hello'.

Update the first_name variable by writing the same value to it, but this time processed by the .strip() method. Print the result.

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.

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