Right way to use lxml to generate xml in python

I'm trying to create xml that corresponds to structure of directory (with subdirectories and files in that subdirs). When i try to use this example: Best way to generate xml in python? instead of output from example, that is:

<root> <child/> <child>some text</child> </root>

i've got:

b'<root>\n  <child/>\n  <child>some text</child>\n</root>\n'

Why it so? Uses PyCharm IDE if it matters.