implement encrypt in vig.py

src/vigenere/vig.py

@@ -1,3 +1,15 @@
+def encrypt(key, plaintext):
+    pln_bytes = bytes(plaintext, 'UTF-8')
+    key_bytes = bytes(key, 'UTF-8')
+    out=""
+
+    for i in range(len(pln_bytes)):
+        pln_chr_index = pln_bytes[i] - 0x61
+        key_chr_index = key_bytes[i % len(key)] - 0x61
+        out_chr_index = (pln_chr_index + key_chr_index) % 26
+        out = out + chr(out_chr_index + 0x61)
+    return out
+
 if __name__ == "__main__":
     import argparse
     parser = argparse.ArgumentParser()
@@ -9,3 +21,4 @@ if __name__ == "__main__":
 
     args = parser.parse_args()
 
+print(encrypt("bbb", "test"))