How to deal with errors like unknown type name 'from'

ROOT
1

I’m getting some errors while running a script in python:
1.unknown type name ‘from’
2.expected ‘;’ after top level declarator**
from array import array
etc

here is the code:

from array import array
import ROOT

myFile = ROOT.TFile.Open(“simplify.root”, “RECREATE”)
tree = ROOT.TTree(“tree”, “newt”)

Provide a one-element array, so ROOT can read data from this memory.

var = array(‘f’, [ 0 ])
tree.Branch(“branch0”, var, “mass”)

for iEntry in range(1000):
var[0] = 0.3 * iEntry
# Fill the current value of ‘var’ into ‘branch0’
tree.Fill()

Now write the header

tree.Write()

2

Hello @wolfram420,
welcome to the ROOT forum!

Could you please attach the full error output?

Cheers
Monica

3

Here is the output:
root [0] .L simp.py

In file included from input_line_8:1:

/afs/ihep.ac.cn/users/c/caoxiaojie/Desktop/simp.py:1:1: error: unknown type name ‘from’

from array import array

^

/afs/ihep.ac.cn/users/c/caoxiaojie/Desktop/simp.py:1:11: error: expected ‘;’ after top level declarator

from array import array

^

;

/afs/ihep.ac.cn/users/c/caoxiaojie/Desktop/simp.py:7:3: error: invalid preprocessing directive

Provide a one-element array, so ROOT can read data from this memory.

^

/afs/ihep.ac.cn/users/c/caoxiaojie/Desktop/simp.py:13:7: error: invalid preprocessing directive

Fill the current value of ‘var’ into ‘branch0’

^

/afs/ihep.ac.cn/users/c/caoxiaojie/Desktop/simp.py:16:3: error: invalid preprocessing directive

Now write the header

Cheers
Lisa

4

You’re trying to execute a python script using a C++ JIT compiler :slight_smile: You should run something like python simp.py

5

Thanks for your reply. The problem is solved :smile: