# Activating the specified CellArrays does not work
**URL:** https://discourse.paraview.org/t/activating-the-specified-cellarrays-does-not-work/13259
**Category:** ParaView Support
**Tags:** python
**Created:** [November 15, 2023, 12:18pm UTC](https://discourse.paraview.org/t/activating-the-specified-cellarrays-does-not-work/13259 "2023-11-15T12:18:39Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@foreverunfree](https://discourse.paraview.org/u/foreverunfree)
#### Post date: [November 15, 2023, 12:18pm UTC](https://discourse.paraview.org/t/activating-the-specified-cellarrays-does-not-work/13259/1 "2023-11-15T12:18:39Z")
Hi,
I use the following code to read the OpenFOAM results and then draw in python. I want to read the specified CellArrays, which I specified with **post\_data** in my code below, but that doesn’t work and I still read up to 24 CellArrays.
```auto
case_path = '/path/to/my/case/case.foam'
post_data = ['T', 'p']
post_time = 0.0012
output_folder = Path("/path/to/my/case/post/slice")
output_folder.mkdir(parents=True, exist_ok=True)
print("Folder created：", output_folder)
multi_block_data = OpenFOAMReader(FileName=case_path, CaseType=1)
if multi_block_data:
print("Successful read.")
else:
print("Failed read.")
multi_block_data.UpdatePipelineInformation()
timesteps = multi_block_data.TimestepValues
print("Available timesteps:", timesteps)
multi_block_data.MeshRegions = ['internalMesh']
print("Selected CellArrays:", multi_block_data.CellArrays.Available)
multi_block_data.CellArrays = post_data
print("Selected CellArrays:", multi_block_data.CellArrays.Available)
multi_block_data.SMProxy.UpdatePipeline(post_time)
print("Selected timestep:", post_time)
print("Selected CellArrays:", multi_block_data.CellArrays.Available)
merged_data = MergeBlocks(Input=multi_block_data)
merged_data.UpdatePipeline()
```
**log**
```auto
Successful read.
Available timesteps: [0.0012, 0.001202, 0.001204, 0.001206, 0.001208, 0.00121, 0.001212, 0.001214, 0.001216, 0.001218, 0.00122, 0.001222, 0.001224, 0.001226, 0.001228, 0.00123, 0.001232, 0.001234, 0.001236, 0.001238, 0.00124, 0.001242, 0.001244, 0.001246, 0.001248, 0.00125, 0.001252, 0.001254, 0.001256, 0.001258, 0.00126, 0.001262, 0.001264, 0.001266, 0.001268, 0.00127, 0.001272, 0.001274, 0.001276, 0.001278, 0.00128, 0.001282, 0.001284, 0.001286, 0.001288, 0.00129, 0.001292, 0.001294, 0.001296, 0.001298, 0.0013, 0.001302, 0.001304, 0.001306, 0.001308, 0.00131, 0.001312, 0.001314, 0.001316, 0.001318, 0.00132, 0.001322, 0.001324, 0.001326, 0.001328, 0.00133, 0.001332, 0.001334, 0.001336, 0.001338, 0.00134, 0.001342, 0.001344, 0.001346, 0.001348, 0.00135, 0.0014, 0.00145, 0.0015]
Selected MeshRegions: ['internalMesh']
Selected CellArrays: ['Chi', 'GradT', 'H', 'H2', 'H2O', 'H2O2', 'H2O2_0', 'H2O_0', 'H2_0', 'HO2', 'HO2_0', 'H_0', 'Ma', 'MagGradT', 'N2', 'O', 'O2', 'O2_0', 'OH', 'OH_0', 'O_0', 'Pmax', 'Qdot', 'Schlieren', 'T', 'U', 'U_0', 'Ydefault', 'alphat', 'fmix', 'fmixVar', 'fmixVar_0', 'fmix_0', 'nut', 'p', 'p_0', 'rho', 'rho_0', 'shadowgraph']
Selected CellArrays: ['Chi', 'GradT', 'H', 'H2', 'H2O', 'H2O2', 'H2O2_0', 'H2O_0', 'H2_0', 'HO2', 'HO2_0', 'H_0', 'Ma', 'MagGradT', 'N2', 'O', 'O2', 'O2_0', 'OH', 'OH_0', 'O_0', 'Pmax', 'Qdot', 'Schlieren', 'T', 'U', 'U_0', 'Ydefault', 'alphat', 'fmix', 'fmixVar', 'fmixVar_0', 'fmix_0', 'nut', 'p', 'p_0', 'rho', 'rho_0', 'shadowgraph']
Selected timestep: 0.0015
Selected CellArrays: ['Chi', 'GradT', 'H', 'H2', 'H2O', 'H2O2', 'H2O2_0', 'H2O_0', 'H2_0', 'HO2', 'HO2_0', 'H_0', 'Ma', 'MagGradT', 'N2', 'O', 'O2', 'O2_0', 'OH', 'OH_0', 'O_0', 'Pmax', 'Qdot', 'Schlieren', 'T', 'U', 'U_0', 'Ydefault', 'alphat', 'fmix', 'fmixVar', 'fmixVar_0', 'fmix_0', 'nut', 'p', 'p_0', 'rho', 'rho_0', 'shadowgraph']
```
---
### Author:  [@utkarsh.ayachit](https://discourse.paraview.org/u/utkarsh.ayachit)
#### Post date: [November 15, 2023, 1:20pm UTC](https://discourse.paraview.org/t/activating-the-specified-cellarrays-does-not-work/13259/2 "2023-11-15T13:20:43Z")
Note, `...CellArrays.Available` will always list all available arrays, even those that are enabled or disabled. The best way to confirm which arrays are read in is to call look at [DataInformation](https://docs.paraview.org/en/latest/UsersGuide/understandingData.html#getting-data-information-in-pvpython) after `UpdatePipeline` call. See the following link for a quick tutorial on how to do this:
ref: [2. Loading Data — ParaView Documentation 5.11.0 documentation](https://docs.paraview.org/en/latest/UsersGuide/dataIngestion.html#id3)
---
### Author:  [@foreverunfree](https://discourse.paraview.org/u/foreverunfree)
#### Post date: [November 15, 2023, 2:10pm UTC](https://discourse.paraview.org/t/activating-the-specified-cellarrays-does-not-work/13259/3 "2023-11-15T14:10:06Z")
Hi,
Thank for your reply, I will try.
However, the results have up to 60 variables, but it loaded 24. I also make a vtk slice of merged\_data, it still have 24 variables. It seems that the cellArrays operation doesn’t work, and I’m still confused about it.
Regards.