df000_simple.py

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## \file
## \ingroup tutorial_dataframe
## \notebook -draw
## Simple RDataFrame example in Python.
##
## This tutorial shows a minimal example of RDataFrame. It starts without input
## data, generates a new column `x` with random numbers, and finally draws
## a histogram for `x`.
##
## \macro_code
## \macro_output
##
## \date September 2021
## \author Enric Tejedor (CERN)
 
import ROOT
 
# Create a data frame with 100 rows
rdf = ROOT.RDataFrame(100)
 
# Define a new column `x` that contains random numbers
rdf_x = rdf.Define("x", "gRandom->Rndm()")
 
# Create a histogram from `x` and draw it
h = rdf_x.Histo1D("x")
h.Draw()