Webapp: NAN values when reading dataset

[Lo96]

Hi, 

I have a webapp based on dash and the i'm performing some etl steps at the dataset before using it in Dash app. The thing is i have NAN values on the dataset and i don't unbderstand why ? at the last step of etl flow , my dataset is consistent (same columns, data points) 

any directions on debuging this ? 

thanks 

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Operating system used: win 10

[Turribeach]

Please share the Python code on you load the dataset in Dask in a code block (the </> icon on the toolbar). Thanks