tcut-to-qastle 0.7

Introduction

TCut selection for ROOT TTree to Qastle wrapper for ServiceX uproot backends.

Supported expressions

• Arithmetic operators: +, -, *, /
• Logical operators: !, &&, ||
• Relational and comparison operators: ==, !=, >, <, >=, <=
• Ternary operator: (A?B:C) - has to be enclosed in parentheses
• Mathematical function: sqrt

Usage

• <tree_name>: Tree name of input flat ROOT ntuple (required only for uproot)
• <selected_columns>: List of selected branches (or columns) to deliver. Branches are separated by comma. Deliver all branches if nothing specified.
• <tcut_selection>: Selection expression with a combination of the branches. No selection is applied if nothing specified.

import tcut_to_qastle

# Get Qastle query
query = tcut_to_qastle.translate(<tree_name>, <selected_columns>, <tcut_selection>)

# Get the list of columns in the TCut selection
columns_in_selection = tcut_to_qastle.get_list_of_columns_in_selection(<TCut selection>)

Example

>>> import tcut_to_qastle
>>> query = tcut_to_qastle.translate("tree", "A,B", "A && B * C>0")
>>> query
"(Select (Where (call EventDataset 'ServiceXDatasetSource' 'tree') (lambda (list event) (and (> (attr event 'A') 0) (> (* (attr event 'B') (attr event 'C')) 0)))) (lambda (list event) (dict (list 'A' 'B') (list (attr event 'A') (attr event 'B')))))"
>>> columns_in_selection = tcut_to_qastle.get_list_of_columns_in_selection("A && B * C>0")
>>> columns_in_selection
['A', 'B', 'C']

Compatibility

Current version is compatible with the following docker image tag of the uproot transformer

• sslhep/servicex_func_adl_uproot_transformer:v1.0.0-rc.3
• sslhep/servicex_func_adl_uproot_transformer:develop

Development

Verbose mode shows intermediate steps from TCut syntax to qastle. The last arguement of the function translate() is a flag to enable the verbose mode. It prints the input TCut selection expression, translated func-adl selection expression, full func-adl query which includes the name of tree and selected branches, and full qastle query.

>>> query = tcut_to_qastle.translate("tree", "A,B", "A && B * C>0", verbose=True)
TCut selection syntax:
A && B * C>0


Translated func-adl selection syntax:
 event.A > 0 and event.B * event.C > 0


Full func-adl query:
EventDataset("ServiceXDatasetSource", "tree").Where("lambda event: event.A > 0 and event.B * event.C > 0 ").Select("lambda event: {'A': event.A, 'B': event.B} ")


Full qastle query:
(Select (Where (call EventDataset 'ServiceXDatasetSource' 'tree') (lambda (list event) (and (> (attr event 'A') 0) (> (* (attr event 'B') (attr event 'C')) 0)))) (lambda (list event) (dict (list 'A' 'B') (list (attr event 'A') (attr event 'B')))))