Snapshotting functions

​

read_snapshots

• Parameters:
  • stream: The name of the stream to read the snapshot for. For example, ‘contacts’.
  • snapshot_dir: The path to the directory where snapshot files are stored.
• Example:
  # Example usage of read_snapshots
  reader = PolarsReader()
  stream_name = 'contacts'
  snapshot_directory = '/path/to/snapshots'
  
  # Read snapshot for the 'contacts' stream
  snapshot_df = reader.read_snapshots(stream=stream_name, snapshot_dir=snapshot_directory)
  
  if snapshot_df is not None:
      print("Snapshot DataFrame:")
      print(snapshot_df)
  else:
      print("No snapshot available.")
  

​

snapshot_records

• Parameters:
  • stream_data: DataFrame (or Lazyframe) containing the new data to be merged.
  • stream: The name of the stream for the snapshots, e.g., ‘contacts’.
  • snapshot_dir: Path to the directory where snapshot files are stored.
  • pk: Primary key(s) to use when merging snapshot; can be a string or a list of strings.
  • just_new: If True, returns just the new data, otherwise returns all merged data.
  • use_csv: If True, saves and reads snapshots in CSV format instead of Parquet.
  • overwrite: If True, overwrites existing snapshot files instead of merging.
• Example:
  import gluestick as gs
  
  # Process only new records
  reader = gs.PolarsReader()
  snapshot_directory = '/path/to/snapshots'
  
  for stream in eval(str(reader)):
      # Get new data
      stream_data = reader.get(stream)
  
      # Update snapshot and get merged data
      merged_df = reader.snapshot_records(
          stream_data=stream_data,
          stream=stream,
          snapshot_dir=snapshot_directory,
          pk=reader.get_pk(stream),
          just_new=False,
          use_csv=False,
          overwrite=False
      )
  
      gs.to_export(df, stream, "./etl-output", keys=[reader.get_pk(stream)])