Error:

File "/tmp/sessions/76bc0639bb20652b/main.py", line 4
print ('Hello,', name, '!')
........................................ ^
IndentationError: unindent does not match any outer indentation level

On the advice, I re-filled the indents with tabs again, everything worked. Thanks to all!
Tell me how to mark a comment with a solution to the question?

Answer 1, authority 100%

In order to copy the “original” whitespace characters from the question, press edit and select and copy the text from the text field.

I pasted this text into Notepad ++:

From this it follows that somewhere you entered a tab character, and somewhere ordinary spaces. For the code to work, the indentation in the method must be the same. In your case, either 4 spaces or a tab character.

Additional information About Indentation in Python Code (PEP 8)

Tabs or spaces?

Spaces are the preferred indentation method.

Tabs should only be used to support tab-indented code.

Python 3 disallows mixing tabs and spaces in indentation.

Python 2 is trying to convert tabs to spaces.

When you invoke the Python 2 interpreter on the command line with the -t option, it will issue warnings when using
mixed style in indentation, and by running the interpreter with the parameter
-tt, you will get errors in these places. These options are highly recommended!