def height(self):
"""Current height of the Merkle-tree
.. note:: Since the tree is binary *balanced*, its height coincides
with the length of its leftmost branch
:rtype: int
"""
length = len(self.leaves)
if length == 0:
return 0
return log_2(length) + 1 if length != 2 ** log_2(length) \
else log_2(length)
def test_log_2(num, expected):
"""Tests log_2 evaluations for all possible combination of powers from 0 to 10
"""
assert utils.log_2(num) == expected
def test_log_2_zero_convention():
"""Tests that log_2 evaluates to 0 for the zero argument
"""
assert utils.log_2(0) == 0
def test_log_2_exception():
"""Tests that log_2 raises ValueError for negative arguments
"""
with pytest.raises(ValueError):
utils.log_2(-1)
