eta_nexus.subscription_handlers.df_subscription_handler module

class eta_nexus.subscription_handlers.df_subscription_handler.DFSubscriptionHandler(write_interval: TimeStep = 1, size_limit: int = 100, *, auto_fillna: bool = True)[source]

Bases: SubscriptionHandler

Subscription handler for returning pandas.DataFrames when requested.

Parameters:

  • write_interval – Interval between index values in the data frame (value to which time is rounded).

  • size_limit – Number of rows to keep in memory.

  • auto_fillna – If True, missing values in self._data are filled with the pandas-method df.ffill() each time self.data is called.

push(node: Node, value: Any | pd.Series | Sequence[Any], timestamp: datetime | pd.DatetimeIndex | TimeStep | None = None) → None[source]

Append values to the dataframe.

Parameters:

  • node – Node object the data belongs to.

  • value – Value of the data or Series of values. There must be corresponding timestamps for each value.

  • timestamp – Timestamp of receiving the data or DatetimeIndex if pushing multiple values. Alternatively an integer/timedelta can be provided to determine the interval between data points. Use negative numbers to describe past data. Integers are interpreted as seconds. If value is a pd.Series and has a pd.DatetimeIndex, timestamp is ignored.

get_latest() → pd.DataFrame | None[source]

Return a copy of the dataframe, this ensures they can be worked on freely. Returns None if data is empty.

property data: pandas.DataFrame

This contains the interval dataframe and will return a copy of that.

reset() → None[source]

Reset the internal data and restart collection.

close() → None[source]

This is just here to satisfy the interface, not needed in this case.