def header_writer(bitwriter,alist):
count=0
for i in range(array_list.length(alist)-1):
if(array_list.get(alist,i) != 0):
count+=1
bitwriter.write_byte(count)
for i in range(array_list.length(alist)-1):
if(array_list.get(alist,i) != 0):
bitwriter.write_byte(i)
bitwriter.write_int(array_list.get(alist,i))
def huffman_encode(input, output):
final_encoded = ''
occurrence_list = count_occurrences(input)
if all (x== None for x in occurrence_list):
output = HuffmanBitsWriter(output)
output.write_code('00')
output.close()
return
olist = count_occurrences(input)
sorted_list = make_sorted_list(occurrence_list)
pairtree = join_leaves(sorted_list)
tree = pairtree.first
code = build_character_code(pairtree.first, occurrence_list)
#code is the occurrence list with the encoded string for each ascII value/index
string = open(input, 'r')
string2 = string.readlines()
string.close()
line = 0
for each in string2:
#if line != 0:
# final_encoded += code[10]
for letter in each: #r.strip()
index = ord(letter)
encoded= code[index]
#print(encoded)
encoded = str(encoded)
final_encoded += encoded
#line += 1
output = HuffmanBitsWriter(output) #open file to write in
#1) The number of codes represented in the Tree as a single 1 byte integer
code_num = number_of_codes(occurrence_list)
output.write_byte(code_num)
#2) Each character c and number of occurrences n as tuple(c, n)
for i in range(array_list.length(olist)):
if olist[i] != None:
output.write_byte(i)
num = olist[i]
num = int(num)
output.write_int(num)
#3) Sequence of bits as encoded string
#print(final_encoded)
for num in final_encoded:
output.write_code(num)
#output.write_code(final_encoded)
output.close()
#need the traverse string of CHARACTERS not ASCII values
string_list = make_character_sorted_list(olist)
string_pairtree = join_leaves(string_list)
stringtree = string_pairtree.first
return traverse(stringtree)
def convert_llist(alist):
llist=None
for i in range(array_list.length(alist)-1):
g=array_list.get(alist, i)
if(g != 0):
llist=linked_list.insert_sorted(llist,Leaf(i,g),comes_before)
return llist
def make_character_sorted_list(occurrence_list):
sorted_list = linked_list.empty_list()
for i in range(array_list.length(occurrence_list)):
if occurrence_list[i] != None:
leaf = make_leaf(chr(i), occurrence_list[i])
sorted_list = linked_list.insert_sorted(sorted_list, leaf, comes_before)
return sorted_list
def test_length1(self):
myList = array_list.empty_list()
self.assertEqual(array_list.length(myList), 0)