Flush python output in Blender 3.0

Question

I have a long running script and would like to be able to see some form of progress indication - a simple print statement would do. From How to show to the user a progression in a script? and https://stackoverflow.com/questions/230751/how-can-i-flush-the-output-of-the-print-function-unbuffer-python-output , I have tried:

import sys

print(msg, flush=True)
sys.write(msg)
sys.stdout.flush()

My script is creating objects based on the contents of a CSV file:

import bpy
import csv
import sys

csvfile = open('c:/temp/input.csv')
inFile = csv.reader(csvfile, delimiter=',', quotechar='"')
# skip header
inFile.__next__()

i=0
for row in inFile:
    if row[0] not in bpy.data.objects:
        size = 0.0002
        x = float(row[0])
        y = float(row[1])
        elev = float(row[2]) / 10
        z = (elev / 2) * size
        bpy.ops.mesh.primitive_cube_add(size=size, enter_editmode=False, align='WORLD', location=(x, y, z), scale=(1, 1, elev))
        materialName = "ourMaterial"
        obj = bpy.context.view_layer.objects.active
        obj.active_material = bpy.data.materials[materialName]
        msg = "%d: %f, %f, %f, %f" % (i, x, y, elev, z)
        print(msg, flush=True)
        sys.stdout.write(msg)
        sys.stdout.flush()

The output does not show in the Blender System window (Window->Toggle System Console).

Is there something else I need to add to the script to pause execution for the output to flush?

Answer 1

Solved thanks to @glorious. I was calling the script from the blender python console with:

filename = 'script.py'
exec(compile(open(filename).read(), filename, 'exec'))

If I execute from the built-in text editor, all is good :-)