mathdatech/Python
1
0
Fork 0
mirror of https://github.com/TheAlgorithms/Python.git synced 2025-04-05 13:26:43 +00:00
Code Issues Packages Projects Releases Wiki Activity

[pre-commit.ci] auto fixes from pre-commit.com hooks

Browse Source 
for more information, see https://pre-commit.ci
This commit is contained in:
pre-commit-ci[bot] 2024-11-21 01:26:02 +00:00
parent 2c279c492d
commit 521d7a23fa
1 changed files with 9 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
compression/ppm.py
View File

@ -2,7 +2,8 @@ from __future__ import annotations
import sys import sys
from collections import defaultdict from collections import defaultdict
#Description for the ppm algorithm can be found at https://en.wikipedia.org/wiki/Prediction_by_partial_matching # Description for the ppm algorithm can be found at https://en.wikipedia.org/wiki/Prediction_by_partial_matching
class PPMNode: class PPMNode:
def __init__(self) -> None: def __init__(self) -> None:
@ -43,7 +44,7 @@ class PPM:
# Encode the symbol based on the current context # Encode the symbol based on the current context
compressed_output.append(self.encode_symbol(context, symbol)) compressed_output.append(self.encode_symbol(context, symbol))
# Update the context by appending the symbol, keeping it within the specified order # Update the context by appending the symbol, keeping it within the specified order
context = (context + symbol)[-self.order:] # Keep the context within order context = (context + symbol)[-self.order :] # Keep the context within order
return compressed_output return compressed_output
@ -73,11 +74,13 @@ class PPM:
if symbol: if symbol:
decompressed_output.append(symbol) decompressed_output.append(symbol)
# Update the context with the newly decoded symbol # Update the context with the newly decoded symbol
context = (context + symbol)[-self.order:] # Keep the context within order context = (context + symbol)[
-self.order :
] # Keep the context within order
else: else:
break # Stop if a symbol cannot be found break # Stop if a symbol cannot be found
return ''.join(decompressed_output) # Join the list into a single string return "".join(decompressed_output) # Join the list into a single string
def decode_symbol(self, context: str, prob: float) -> str | None: def decode_symbol(self, context: str, prob: float) -> str | None:
# Decode a symbol from the given context based on the probability # Decode a symbol from the given context based on the probability
@ -98,7 +101,7 @@ class PPM:
def read_file(file_path: str) -> str: def read_file(file_path: str) -> str:
"""Read the entire file and return its content as a string.""" """Read the entire file and return its content as a string."""
with open(file_path, 'r') as f: with open(file_path, "r") as f:
return f.read() return f.read()
@ -123,4 +126,4 @@ if __name__ == "__main__":
sys.exit(1) sys.exit(1)
# Call the ppm function with the provided file path # Call the ppm function with the provided file path
ppm(sys.argv[1]) ppm(sys.argv[1])