--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/puppy/helpers.py	Sun Oct 24 15:18:54 2021 +0200
@@ -0,0 +1,41 @@
+import hashlib
+
+
+def __get_hash(buffer, bytes_order='backward'):
+    """
+    Compute hash from bytes
+    More info about bytes order: https://en.wikipedia.org/wiki/Endianness
+    :param buffer: bytes, required
+    :param bytes_order: string, 'backward' or 'forward', optional
+    :return: string
+    """
+
+    h = hashlib.sha256(buffer).digest()
+    h = hashlib.sha256(h).digest()
+
+    if bytes_order == 'backward':
+        h = h[::-1]
+
+    return h.hex()
+
+
+def __get_variable_int(f):
+    """
+    Get variable int from transaction data
+    More info: https://learnmeabitcoin.com/technical/varint
+    :param f: buffer, required
+    :return: int
+    """
+
+    first_byte = f.read(1)
+
+    if first_byte == b'\xfd':
+        variable_int_bytes = f.read(2)[::-1]
+    elif first_byte == b'\xfe':
+        variable_int_bytes = f.read(4)[::-1]
+    elif first_byte == b'\xff':
+        variable_int_bytes = f.read(8)[::-1]
+    else:
+        variable_int_bytes = first_byte
+
+    return int.from_bytes(variable_int_bytes, 'little')