# Dynamic number of outputs for reader

**URL:** https://discourse.paraview.org/t/dynamic-number-of-outputs-for-reader/10891
**Category:** ParaView Support
**Created:** [November 30, 2022, 10:59pm UTC](https://discourse.paraview.org/t/dynamic-number-of-outputs-for-reader/10891 "2022-11-30T22:59:23Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Juan\_Jose\_Casafranca](https://discourse.paraview.org/user_avatar/discourse.paraview.org/juan_jose_casafranca/32/3499_2.png) [@Juan\_Jose\_Casafranca](https://discourse.paraview.org/u/Juan_Jose_Casafranca)
#### Post date: [November 30, 2022, 10:59pm UTC](https://discourse.paraview.org/t/dynamic-number-of-outputs-for-reader/10891/1 "2022-11-30T22:59:23Z")

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I have a cloth simulator and I am writing the output of the simulations in an HDF5 container. My simulations may contain a positive number of certain objects. For example, it may contain between N buttons.

I am creating a reader for paraview to load our simulation results. However, I am not sure how to set the number of objects that the reader outputs, as different simulations may have different number of buttons.

Is it possible to read a dynamic value of vtkUnstructuredGrids using a single custom python reader?