incosistent behaviour on ptpython

[wzy]

Describe the bug

from torchvision.models import resnet18
from torchinfo import summary
model = resnet18()
a = summary(model, (1, 3, 256, 256))

In python, ipython, this code will not output anything, however, in ptpython, it will output a.

Expected behavior
in any REPL of python, it shouldn't output.

Screenshots

ptpython: 3.0.21
python: 3.10.9
torchinfo: 1.7.1

Additional context
Add any other context about the problem here.

[wzy]

Oh, it looks related to sys.ps1.

[wzy]

This code use sys.ps1 to detect if it is a REPL, however, python and ipython assign sys.ps1 while ptpython not.