fast_carpenter.selection package

class fast_carpenter.selection.CutFlow(name, out_dir, selection_file=None, keep_unique_id=False, selection=None, counter=True, weights=None)[source]

Bases: object

Prevents subsequent stages seeing certain events.

The two most important parameters to understand are the selection and weights parameters.

  • selection (str or dict) – The criteria for selecting events, formed by a nested set of “cuts”. Each cut must either be a valid Expressions or a single-length dictionary, with one of Any or All as the key, and a list of cuts as the value.
  • weights (str or list[str], dict[str, str]) – How to weight events in the output summary table. Must be either a single variable, a list of variables, or a dictionary where the values are variables in the data and keys are the column names that these weights should be called in the output tables.


Mask events using a single cut based on the nJet variable being greater than 2 and weight events in the summary table by the EventWeight variable:

        nJet > 2
    weights: EventWeight

Mask events by requiring both the nMuon variable being greater than 2 and the first Muon_energy value in each event being above 20. Don’t weight events in the summary table:

          - nMuon > 2
          - {reduce: 0, formula: Muon_energy > 20}

Mask events by requiring the nMuon variable be greater than 2 and either the first Muon_energy value in each event is above 20 or the total_energy is greater than 100. The summary table will weight events by both the EventWeight variable (called weight_nominal in the table) and the SystUp variable (called weight_syst_up in the summary):

          - nMuon > 2
          - Any:
            - {reduce: 0, formula: Muon_energy > 20}
            - total_energy > 100
    weights: {weight_nominal: EventWeight, weight_syst_up: SystUp}
Other Parameters:
  • name (str) – The name of this stage (handled automatically by fast-flow)
  • out_dir (str) – Where to put the summary table (handled automatically by fast-flow)
  • selection_file (str) – Deprecated
  • keep_unique_id (bool) – If True, the summary table will contain a column that gives each cut a unique id. This is used internally to maintain the cut order, and often will not be useful in subsequent manipulation of the output table, so by default this is removed.
  • counter (bool) – Currently unused

BadCutflowConfig – If neither or both of selection and selection_file are provided, or if a bad selection or weight configuration is given.

See also

SelectPhaseSpace: Adds the resulting event-mask as a new variable to the data.

selection.filters.build_selection(): Handles the actual creation of the event selection, based on the configuration.

numexpr: which is used for the internal expression handling.

class fast_carpenter.selection.SelectPhaseSpace(name, out_dir, region_name, **kwargs)[source]

Bases: fast_carpenter.selection.stage.CutFlow

Creates an event-mask and adds it to the data-space.

This is identical to the CutFlow class, except that the resulting mask is added to the list of variables in the data-space, rather than being used directly to remove events. This allows multiple “regions” to be defined using different CutFlows in a single configuration.

Parameters:region_name – The name given to the resulting mask when added to back to the data-space.

See also

CutFlow: for a description of the other parameters.