Hi, I am trying to create an app the user can upload a file and choose which columns to plot in x-axis and y-axis of the bar chart. However, when I put dropdown as input value in the callback of the graph, I get Error loading dependencies. Any idea where I got it wrong?
Thanks a mil!
Below is my code:
import base64
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 plotly.graph_objs as go
from dash.exceptions import PreventUpdate
external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']
app = dash.Dash(__name__, external_stylesheets=external_stylesheets)
app.config.suppress_callback_exceptions = True
app.layout = html.Div([
dcc.Upload(
id='datatable-upload',
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'
},
),
html.Div(id='output-data-upload'),
dcc.Dropdown(
id='data_selector1',
options=[
{'label': '', 'value': ''}
],
value=[]
),
dcc.Dropdown(
id='data_selector2',
options=[
{'label': '', 'value': ''}
],
value=[]
),
dcc.Graph(id='datatable-upload-graph')
])
def parse_contents(contents, filename):
content_type, content_string = contents.split(',')
decoded = base64.b64decode(content_string)
if 'csv' in filename:
# Assume that the user uploaded a CSV file
return pd.read_csv(
io.StringIO(decoded.decode('utf-8')))
elif 'xls' in filename:
# Assume that the user uploaded an excel file
return pd.read_excel(io.BytesIO(decoded))
@app.callback(Output('output-data-upload', 'children'),
[Input('datatable-upload', 'contents')],
[State('datatable-upload', 'filename')])
def update_output(contents, filename):
if contents is None:
return []
df = parse_contents(contents, filename)
return html.Div([
dash_table.DataTable(
id='table',
style_data={
'whiteSpace': 'normal',
'height': 'auto'
},
style_table={'overflowX': 'scroll',
'maxHeight': '300',
'overflowY': 'scroll'},
style_cell={
'minWidth': '150px', 'maxWidth': '180px',
'whiteSpace': 'normal',
'textAlign': 'left'
},
style_header={
'fontWeight': 'bold',
},
fixed_rows={ 'headers': True, 'data': 0 },
columns=[{"name": i, "id": i, 'deletable': True, 'renamable': True} for i in df.columns],
data=df.to_dict("records"),
row_deletable=True,
filter_action="native",
sort_action="native",
sort_mode='multi',
editable=True,
)
])
@app.callback(Output('data_selector1', 'options'),
[Input('table', 'data')])
def update_dropdown(rows):
if rows is None:
raise PreventUpdate
df = pd.DataFrame(rows)
print('updating menus')
columns=df.columns
col_labels=[{'label' :k, 'value' :k} for k in columns]
return col_labels
@app.callback(Output('data_selector2', 'options'),
[Input('table', 'data')])
def update_dropdown2(rows):
if rows is None:
raise PreventUpdate
df = pd.DataFrame(rows)
print('updating menus')
columns=df.columns
col_labels=[{'label' :k, 'value' :k} for k in columns]
return col_labels
@app.callback(Output('datatable-upload-graph', 'figure'),
[Input('data_selector1', 'value'), # I get the Error when i put this two input
Input('data_selector2', 'value')],
[State('table', 'data')])
def display_graph(value1, value2, rows):
df = pd.DataFrame(rows)
trace1 = go.Bar(x=df[value1], y=df[value2], name='Active')
return {
'data': [trace1]
}
if __name__ == '__main__':
app.run_server(debug=True)