Refactored code.

datalite/commons.py

@@ -0,0 +1,36 @@
+from typing import Any, Optional, Dict
+
+
+def _convert_type(type_: Optional[type], type_overload: Dict[Optional[type], str]) -> str:
+    """
+    Given a Python type, return the str name of its
+    SQLlite equivalent.
+    :param type_: A Python type, or None.
+    :param type_overload: A type table to overload the custom type table.
+    :return: The str name of the sql type.
+    >>> _convert_type(int)
+    "INTEGER"
+    """
+    try:
+        return type_overload[type_]
+    except KeyError:
+        raise TypeError("Requested type not in the default or overloaded type table.")
+
+
+def _convert_sql_format(value: Any) -> str:
+    """
+    Given a Python value, convert to string representation
+    of the equivalent SQL datatype.
+    :param value: A value, ie: a literal, a variable etc.
+    :return: The string representation of the SQL equivalent.
+    >>> _convert_sql_format(1)
+    "1"
+    >>> _convert_sql_format("John Smith")
+    '"John Smith"'
+    """
+    if isinstance(value, str):
+        return f'"{value}"'
+    elif isinstance(value, bytes):
+        return '"' + str(value).replace("b'", "")[:-1] + '"'
+    else:
+        return str(value)