_rntuple.pyzdoc

Go to the documentation of this file.

\pythondoc RNTupleWriter
 
RNTupleWriter is an interface to write RNTuples to storage.
 
A simple way to write an RNTuple in python is by:
- creating a model and adding fields to it
- opening an RNTupleWriter 
- creating entries and filling them with data
- committing entries to the RNTuple via writer.Fill(entry)
 
\code{.py}
import ROOT
 
# Create the model
model = ROOT.RNTupleModel.Create()
 
# Define the schema by adding fields to the model.
model.MakeField['int']("foo")
 
# Create a writer as a context manager
with ROOT.RNTupleWriter.Recreate(model, "myNtuple", "file.root") as writer:
    # create an entry and use it to write data to the RNTuple
    entry = writer.CreateEntry()
    for i in range(0,10):
        entry['foo'] = i
        writer.Fill(entry)
# On destruction, the writer will flush the written data to disk
 
\endcode
 
\endpythondoc