Structure for applying a function in dash

Dash Python
1

Hey,

I am trying to figure out the following process. I am trying to upload a csv file and apply a function to it by calling a python script. The csv results after applying the function should be displayed in a interactive dash table .

I think I might be having some troubles with the callbacks.

import base64
import datetime
import io

import dash
from dash.dependencies import Input, Output, State
import dash_core_components as dcc
import dash_html_components as html
import dash_table

import pandas as pd
import spacy
import results_table

external_stylesheets = [‘https://codepen.io/chriddyp/pen/bWLwgP.css’]

app = dash.Dash(name, external_stylesheets=external_stylesheets)

app.layout = html.Div([
dcc.Upload(
id=‘upload-data’,
children=html.Div([
'Drag and Drop or ',
html.A(‘Select Files’)
]),
style={
‘width’: ‘100%’,
‘height’: ‘60px’,
‘lineHeight’: ‘60px’,
‘borderWidth’: ‘1px’,
‘borderStyle’: ‘dashed’,
‘borderRadius’: ‘5px’,
‘textAlign’: ‘center’,
‘margin’: ‘10px’
},
# Allow multiple files to be uploaded
multiple=True
),
html.Div(id=‘output-data-upload’),
dash_table.DataTable(
id=‘results_table’,
columns=[
{‘name’: ‘name’, ‘id’: ‘name’}]
)
#dash_table.DataTable(id=‘results_table’, rows=[{}])

])

def parse_contents(contents, filename, date):
content_type, content_string = contents.split(’,’)

decoded = base64.b64decode(content_string)
try:
    if 'csv' in filename:
        # Assume that the user uploaded a CSV file
        df = pd.read_csv(
            io.StringIO(decoded.decode('utf-8')))
    elif 'xls' in filename:
        # Assume that the user uploaded an excel file
        df = pd.read_excel(io.BytesIO(decoded))
except Exception as e:
    print(e)
    return html.Div([
        'There was an error processing this file.'
    ])

return html.Div([
    html.H5(filename),
    html.H6(datetime.datetime.fromtimestamp(date)),

    dash_table.DataTable(
        data=df.to_dict('records'),
        columns=[{'name': i, 'id': i} for i in df.columns]
    ),

    html.Hr(),  # horizontal line

    # For debugging, display the raw contents provided by the web browser
    html.Div('Raw Content'),
    html.Pre(contents[0:200] + '...', style={
        'whiteSpace': 'pre-wrap',
        'wordBreak': 'break-all'
    })
])

@app.callback(Output(‘output-data-upload’, ‘children’),
[Input(‘upload-data’, ‘contents’)],
[State(‘upload-data’, ‘filename’),
State(‘upload-data’, ‘last_modified’)])
def update_output(list_of_contents, list_of_names, list_of_dates):
if list_of_contents is not None:
children = [
parse_contents(c, n, d) for c, n, d in
zip(list_of_contents, list_of_names, list_of_dates)]
return children

@app.callback(dash.dependencies.Output(‘results_table’, ‘data’),
[dash.dependencies.Input(‘upload-data’, ‘children’)])

def display_(filedata):
df = results_table.classify(filedata)

return df.to_dict(orient='records')

if name == ‘main’:
app.run_server()

The python script is as follows:
import pandas as pd
import spacy
import os

def apply_model1(df):
docs = nlp(df)
return docs.cats

def apply_model2(df):
docs2 = nlp1(df)
return docs2.cats

def classify(filedata):
nlp = spacy.load(“C:/Users/srini/Desktop/dash/process_nonprocess_classification”)
nlp1 = spacy.load(“C:/Users/srini/Desktop/dash/tmp_prs_flw_model”)
df1 = pd.DataFrame(columns=[‘result1’, ‘result2’])
df1[‘result1’] = filedata[‘name’].apply(apply_model1)
df1[‘result2’] = filedata[‘name’].apply(apply_model2)
return df1

Any help would be much appreciated