def test_joined(self):
code = ""
for i in range(1, 1000):
code += l_elias_encoder.encode_single_value(i)
for i in range(1, 1000):
decoded = l_elias_decoder.decode_single_value(code)
code = code[len(l_elias_encoder.encode_single_value(i)) :]
assert i == decoded
def encode_header(code):
res = unique_chars(code)
# Total number of unique characters
result = l_elias_encoder.encode_single_value(len(res))
for val in res:
# Frequency of each character
result += l_elias_encoder.encode_single_value(res[val])
# ASCII code of character padded to 3 digits.
result += "{0:0=3d}".format(ord(val))
# Total number of characters in the input file.
result += l_elias_encoder.encode_single_value(len(code))
return result
def decode(code):
# Calculate no of unique and remove from code.
no_of_unique = l_elias_decoder.decode_single_value(code)
no_of_unique_encoded = l_elias_encoder.encode_single_value(no_of_unique)
code = code[len(no_of_unique_encoded):]
frequencies = {}
for i in range(no_of_unique):
freq = l_elias_decoder.decode_single_value(code)
freq_encoded = l_elias_encoder.encode_single_value(freq)
code = code[len(freq_encoded):]
char = chr(int(code[0:3]))
code = code[3:]
frequencies[char] = freq
total_chars = l_elias_decoder.decode_single_value(code)
total_chars_encoded = l_elias_encoder.encode_single_value(total_chars)
code = code[len(total_chars_encoded):]
heap = []
for val in frequencies:
node = Node(val, frequencies[val])
heapq.heappush(heap, node)
root = heap[0]
while len(heap) > 1:
min1: Node = heapq.heappop(heap)
min2: Node = heapq.heappop(heap)
new_node = Node(min1.char + min2.char, min1.count + min2.count)
new_node.left = min1
new_node.right = min2
root = new_node
heapq.heappush(heap, new_node)
result = ""
for i in range(total_chars):
res = search_for_char(root, "", code, -1)
result += res[1]
code = code[len(res[0]):]
return result
def test_all(self):
for i in range(1, 100000):
code = l_elias_encoder.encode_single_value(i)
decoded = l_elias_decoder.decode_single_value(code)
assert i == decoded
def test_from_lecture_slides(self):
"""Test using example from lecture slides."""
expected = "00100011000110001"
assert l_elias_encoder.encode_single_value(561) == expected