Merge pull request #37 from bhoomikahm-123/main

Add Text Compression File#26

Text_Compression.py

@@ -0,0 +1,78 @@
+# Node class to store characters and their frequencies
+class Node:
+    def __init__(self, char, freq):
+        self.char = char
+        self.freq = freq
+        self.left = None
+        self.right = None
+    def __lt__(self, other):
+        return self.freq < other.freq
+
+# Function to calculate frequencies of characters in the given text
+def calculate_frequencies(text):
+    freq = {}
+    for char in text:
+        if char not in freq:
+            freq[char] = 0
+        freq[char] += 1
+    return freq
+
+# Function to build the Huffman Tree
+def build_huffman_tree(frequencies):
+    nodes = [Node(char, freq) for char, freq in frequencies.items()]
+    while len(nodes) > 1:
+        nodes = sorted(nodes, key=lambda x: x.freq)
+        left = nodes.pop(0)
+        right = nodes.pop(0)
+        new_node = Node(None, left.freq + right.freq)
+        new_node.left = left
+        new_node.right = right
+        nodes.append(new_node)
+    return nodes[0]
+
+# Function to generate the Huffman Codes by traversing the tree
+def generate_huffman_codes(node, current_code="", codes={}):
+    if node is None:
+        return
+    if node.char is not None:
+        codes[node.char] = current_code
+    generate_huffman_codes(node.left, current_code + "0", codes)
+    generate_huffman_codes(node.right, current_code + "1", codes)
+    return codes
+
+# Function to encode the text using the Huffman Codes
+def encode_text(text, huffman_codes):
+    encoded_text = ""
+    for char in text:
+        encoded_text += huffman_codes[char]
+    return encoded_text
+
+# Function to decode the encoded text back to the original text
+def decode_text(encoded_text, root):
+    decoded_text = ""
+    current_node = root
+    for bit in encoded_text:
+        if bit == '0':
+            current_node = current_node.left
+        else:
+            current_node = current_node.right
+        if current_node.char is not None:
+            decoded_text += current_node.char
+            current_node = root
+    return decoded_text
+
+# Main function to execute Huffman Coding
+def huffman_coding(text):
+    frequencies = calculate_frequencies(text) #Step 1
+    huffman_tree_root = build_huffman_tree(frequencies) #Step2
+    huffman_codes = generate_huffman_codes(huffman_tree_root) #Step3
+    encoded_text = encode_text(text, huffman_codes) #Step4
+    decoded_text = decode_text(encoded_text, huffman_tree_root) #Step5
+    print("Original Text:", text)
+    print("Character Frequencies:", frequencies)
+    print("Huffman Codes:", huffman_codes)
+    print("Encoded Text:", encoded_text)
+    print("Decoded Text:", decoded_text)
+
+sample_text = "BCAADDDCCACACAC"
+huffman_coding(sample_text)