feat: persist empty tables

tests/test_tables.py

@@ -169,3 +169,11 @@ def test_table_repr(db):
 def test_truncate_table(db):
  db.truncate()
  assert db._get_next_id() == 1
+
+
+def test_persist_table(db):
+ db.table("persisted", persist_empty=True)
+ assert "persisted" in db.tables()
+
+ db.table("nonpersisted", persist_empty=False)
+ assert "nonpersisted" not in db.tables()

tinydb/table.py

@@ -72,6 +72,7 @@ class Table:
  :param storage: The storage instance to use for this table
  :param name: The table name
  :param cache_size: Maximum capacity of query cache
+ :param persist_empty: Store new table even with no operations on it
  """
 
  #: The class used to represent documents
@@ -98,7 +99,8 @@ def __init__(
  self,
  storage: Storage,
  name: str,
- cache_size: int = default_query_cache_capacity
+ cache_size: int = default_query_cache_capacity,
+ persist_empty: bool = False
  ):
  """
  Create a table instance.
@@ -110,6 +112,8 @@ def __init__(
  = self.query_cache_class(capacity=cache_size)
 
  self._next_id = None
+ if persist_empty:
+ self._update_table(lambda table: table.clear())
 
  def __repr__(self):
  args = [
@@ -163,7 +167,7 @@ def updater(table: dict):
  if doc_id in table:
  raise ValueError(f'Document with ID {str(doc_id)} '
  f'already exists')
- 
+
  # By calling ``dict(document)`` we convert the data we got to a
  # ``dict`` instance even if it was a different class that
  # implemented the ``Mapping`` interface
@@ -676,7 +680,7 @@ def _read_table(self) -> Dict[str, Mapping]:
  """
  Read the table data from the underlying storage.
 
- Documents and doc_ids are NOT yet transformed, as 
+ Documents and doc_ids are NOT yet transformed, as
  we may not want to convert *all* documents when returning
  only one document for example.
  """