Dash datatable import multiple files

Dash Python
1

Hello all,

First of all, I’ve been looking at many posts and links on the web and didn’t found any answer to my problem. So, basically I am building a webapp, which is reading datafiles (txt; csv or dat) using dcc.Upload. As far as I know, I found a topic where someone explained that dcc.Upload was bugged and wasn’t really able to import multiple files. BUT : I managed to do it and get the list of filenames clickes in the upload window. This done, I called as a callback a function that will process the file and return a dataFrame with 9 columns. 2 of them contain arrays of data. :

def update_output(list_of_contents, list_of_names, list_of_dates):
    print(list_of_names)
    dicData=[]
    j=0
    if list_of_contents is not None:
        
        c, n, d = list(zip(list_of_contents, list_of_names, list_of_dates))[0]
        for i in list_of_names:
            dataTemp=parseFiles.openDataFile(c, i, d).iloc[:, :]
            dataTemp.columns=columns_data
            dataTemp=dataTemp.to_dict("records")
            dicData.append([dataTemp])


            j+=1 

        try:
            #print(dicData)
            return dicData
        except:
            pass

So my problem is that everything goes well until I return the dicData list of dicts to the dataTable. For example, if I select 3 files, 3 rows are appearing, but nothing in the cells. I guess it’s a problem of data formatting that are taken in the cells, but I have many difficulties to figure it out. Maybe you could help me?

Thank you in advance :wink:

2

You must pass columns list too formatted like columns=[{“name”: i, “id”: i} for in columns_list]

3

Hello Jorge, thanks for your answer. Actually that’s what I did out of the function. I tried with it inside the function, but still the same :

columns_data = ["File name", "Record", "Sample", "T (°C)", "Viscos.", "Angle (°)", "RI", "Time", "Gamma"]
4

I found it out by myself. Actually I have to return a dataFrame directly from my parsing function and then I am able to loop on it and transform it into a dict.

5

Was wondering if you could post your final code. Struggling with this now