Keep single quotes in InsertIntoWriter (#128)

InsertIntoWriter converts a single quote to a double quote because
single quotes are reserved for string literals and double quotes are
column name.

However, this conversion will break users characters when their data
have a single quote.
For example, current behavior changes `St. Patrick's day` to `St.
Patrick"s day` implicitly.

To eliminate this issue, this pull request aims to keep single quotes.

Author: akito19

pytd/writer.py

@@ -286,9 +286,13 @@ def _build_query(self, database, table, list_of_tuple, column_names):
         """
         rows = []
         for tpl in list_of_tuple:
+            # InsertIntoWriter kicks Presto (Trino).
+            # Following the list comprehension makes a single quote duplicated because
+            # Presto allows users to escape a single quote with another single quote.
+            # e.g. 'John Doe''s name' is converted to "John Doe's name" on Presto.
             list_of_value_strings = [
                 (
-                    f"""'{e.replace("'", '"')}'"""
+                    f"""'{e.replace("'", "''")}'"""
                     if isinstance(e, str)
                     else ("null" if pd.isnull(e) else str(e))
                 )