Implement basis of tally-token

README.md

@@ -14,6 +14,24 @@ tally-token is a Python library for split data into tokens with same length.
 $ pip install tally-token
 ```
 
+## Example
+
+### split
+
+```python
+>>> from tally_token import split_text
+>>> split_text("Hello, World!")
+(b'qQ\xa5\x97\x84\x88\xd7U%\xfb(k\xa1', b'94\xc9\xfb\xeb\xa4\xf7\x02J\x89D\x0f\x80')
+```
+
+### merge
+
+```python
+>>> from tally_token import merge_text
+>>> merge_text(b'qQ\xa5\x97\x84\x88\xd7U%\xfb(k\xa1', b'94\xc9\xfb\xeb\xa4\xf7\x02J\x89D\x0f\x80')
+'Hello, World!'
+```
+
 # LICENSE
 
 BSD 3-Clause License

tally_token/__init__.py

@@ -0,0 +1,32 @@
+from __future__ import annotations
+
+import secrets
+
+
+def _generate_random_token(size: int) -> bytes:
+    # TODO: seed
+    return secrets.token_bytes(size)
+
+
+def split_text(clear_text: str) -> tuple[bytes, bytes]:
+    clear_text_bytes = bytes(clear_text, "utf-8")
+    return split1(clear_text_bytes)
+
+
+def split1(source: bytes) -> tuple[bytes, bytes]:
+    token = _generate_random_token(len(source))
+    cipher_text = bytearray()
+    for i in range(len(source)):
+        cipher_text.append(source[i] ^ token[i])
+    return bytes(token), bytes(cipher_text)
+
+
+def merge1(token1: bytes, token2: bytes) -> bytes:
+    clear_text = bytearray()
+    for i in range(len(token1)):
+        clear_text.append(token1[i] ^ token2[i])
+    return bytes(clear_text)
+
+
+def merge_text(token: bytes, cipher_text: bytes) -> str:
+    return merge1(token, cipher_text).decode("utf-8")

tests/test_basis.py

@@ -0,0 +1,8 @@
+from tally_token import split_text, merge_text
+
+
+def test_split_merge():
+    """Test that split_text and merge_text are inverses."""
+    clear_text = "Hello World!"
+    token1, token2 = split_text(clear_text)
+    assert clear_text == merge_text(token1, token2)