Yes, currently the C version is also used for unpickling. Actually
this problem was one of the reasons why _decimal sets its name to
"decimal".
 


from test.support import import_fresh_module
import pickle, sys

C = import_fresh_module('xml.etree.ElementTree', fresh=['_elementtree'])
P = import_fresh_module('xml.etree.ElementTree', blocked=['_elementtree'])
e = C.Element('foo', bar=42)
e.text = "text goes here"
e.tail = "opposite of head"
C.SubElement(e, 'child').append(C.Element('grandchild'))
e.append(C.Element('child'))
e.findall('.//grandchild')[0].set('attr', 'other value')
sys.modules['xml.etree.ElementTree'] = C 
s = pickle.dumps(e)
s

b'\x80\x03c_elementtree\nElement\nq\x00X\x03\x00\x00\x00fooq\x01}q\x02X\x03\x00\x00\x00barq\x03K*s\x86q\x04Rq\x05X
\x0e\x00\x00\x00text goes hereq\x06X\x10\x00\x00\x00opposite of headq\x07h\x00X\x05\x00\x00\x00childq\x08\x85q\tRq
\nNNh\x00X\n\x00\x00\x00grandchildq\x0b}q\x0cX\x04\x00\x00\x00attrq\rX\x0b\x00\x00\x00other valueq\x0es\x86q\x0fRq
\x10NNN\x87q\x11b\x85q\x12\x87q\x13bh\x00h\x08\x85q\x14Rq\x15NNN\x87q\x16b\x86q\x17\x87q\x18b.'

sys.modules['xml.etree.ElementTree'] = P
x = pickle.loads(s)
type(x)
<class '_elementtree.Element'>