def test_pstring_collection_empty():
pauli_collection = PauliStringCollection()
assert pauli_collection.elements == []
assert pauli_collection.elements_by_weight == {}
assert pauli_collection.min_weight() == 0
assert pauli_collection.support() == set()
assert len(pauli_collection) == 0
def test_pstringcollection():
x = PauliString(spec="X")
iz = PauliString(spec="IZ")
xz = PauliString(spec="XZ")
xzixx = PauliString(spec="XZIXX")
pauli_collection = PauliStringCollection(x, iz, xz, xzixx)
assert pauli_collection.elements == [x, iz, xz, xzixx]
assert pauli_collection.elements_by_weight == {
1: Counter((x, iz)),
2: Counter((xz,)),
4: Counter((xzixx,)),
}
assert pauli_collection.min_weight() == 1
assert pauli_collection.max_weight() == 4
assert pauli_collection.support() == {0, 1, 3, 4}
assert len(pauli_collection) == 4