Python: The immutability of primitive types

Imagine that we need to change a character in a string. This is what will come out of it:

first_name = 'Alexander'
first_name[0] = 'B'
# Error: TypeError: 'str' object does not support item assignment

This happens because of the immutability of primitive types in Python - the language does not give any physical possibility to change the string. The immutability of primitive types is important for many reasons. The key reason is performance.

But sometimes we need to change a string. That's what variables are for:

first_name = 'Alexander'
first_name = 'Blexander'
print(first_name)  # => Blexander

There is a big difference between changing the value of a variable and changing the value itself. You can't change primitive types in Python, but you can change composite types. You can also change the value of a variable without any problem.

Instructions

You are given three variables with the names of different people. Make and display a word of characters in this order:

The third character from the first line
The second character from the second line
The fourth character from the third line
The fifth character of the second line
The third character from the second line

Try using interpolation: not only whole variables can be placed inside curly brackets, but also individual characters using square brackets.

Коммерческий опыт и Трудоустройство

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 🤨

My code is different from the teacher's one 🤔

I've read the lessons but nothing is clear 🙄

Прочитал урок — ничего не понятно 🙄

Found a bug? Have something to add? Pull requests are welcome!

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Your exercise will be checked with these tests:

import importlib


def test(capsys):
    expected = "print"
    expect_output(capsys, expected)


def expect_output(capsys, expected):
    importlib.import_module('solution')
    out, _err = capsys.readouterr()
    actual = out.strip('\n')

    with capsys.disabled():
        print('\n')
        print(out)

    assert actual == expected

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Teacher's solution will be available in:

20:00

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