Move eval script

text_codecs/evaluate.py

@@ -0,0 +1,75 @@
+from argparse import ArgumentParser
+from pathlib import Path
+import codecs
+import requests
+from tabulate import tabulate
+import sys
+import shutil
+
+codecs_dir = "text_codecs"
+
+def evaluate_encoding(encoding, text_path):
+    ""
+    print(f"Evaluating encoding {encoding}")
+    try:
+        codecs.lookup(encoding)
+    except LookupError:
+        __import__(encoding)
+    text = Path(text_path).read_text()
+    compressed_path = Path(text_path).with_suffix('.' + encoding)
+    if compressed_path.exists():
+        compressed = compressed_path.read_bytes()
+    else:
+        compressed = text.encode(encoding)
+        compressed_path.write_bytes(compressed)
+    original_size = len(text.encode('utf8'))
+    compressed_size = len(compressed)
+    return {
+        'encoding': encoding, 
+        'original': original_size,
+        'compressed': compressed_size,
+        'compression_rate': compressed_size / original_size
+    }
+
+def inspect_encoded_text(encoding, text_path):
+    try:
+        codecs.lookup(encoding)
+    except LookupError:
+        __import__(encoding)
+    compressed_path = Path(text_path).with_suffix('.' + encoding)
+    if not compressed_path.exists():
+        compressed = Path(text_path).read_text().encode(encoding)
+        compressed_path.write_bytes(compressed)
+    with open(compressed_path, 'rb') as fh:
+        text = fh.read().decode(encoding)
+        return text
+
+text_dir = Path("texts")
+default_text = "texts/little_women.txt"
+default_text_url = "https://www.gutenberg.org/cache/epub/37106/pg37106.txt"
+
+parser = ArgumentParser("A command-line tool which measures compression rates.")
+parser.add_argument("encodings", nargs="*")
+parser.add_argument("--inspect", "-i", help="See resulting text for a codec")
+parser.add_argument("--text", "-t", default="texts/little_women.txt", help="Text file to use for testing")
+parser.add_argument("--clean", "-c", action="store_true", help="Remove all generated files")
+args = parser.parse_args()
+if args.clean:
+    shutil.rmtree(text_dir)
+if not text_dir.exists():
+    text_dir.mkdir()
+if not Path(args.text).exists():
+    if args.text == default_text:
+        print("Downloading 'little_women.txt' from Project Gutenberg...")
+        response = requests.get(default_text_url, stream=True)
+        with open(default_text, 'wb') as f:
+            f.write(response.content)
+    else:
+        raise ValueError(f"{args.text} does not exist")
+sys.path.append(codecs_dir)
+if args.encodings:
+    results = [evaluate_encoding(e, args.text) for e in args.encodings]
+    print(tabulate(results, headers="keys"))
+if args.inspect:
+    print(inspect_encoded_text(args.inspect, args.text))
+