As titled, i am creating a plotly dashboard with a data-table only. There will be 2 drop-downs as inputs, and the data-table will update according to the drown-downs. How do I set the layout and callbacks?
import pandas as pd
import dash
import dash_core_components as dcc
import dash_html_components as html
import dash_table as dt
from dash.dependencies import Input, Output, State
df = pd.read_csv(data, header=0, encoding = 'utf8')
app = dash.Dash()
application = app.server
dropdown = html.Div([html.Label('district'),
dcc.Dropdown(id='dropdown_d',
options=[{'label': i, 'value': i} for i in df["district"].unique()], value='none'),
html.Label('address'),
dcc.Dropdown(id='dropdown_a',
options=[{'label': i, 'value': i} for i in df["address"].unique()], value='none')])
final_table = html.Div([dash_table.DataTable(id="final_table")])
app.layout = html.Div([dropdown, final_table])
@app.callback(Output('final_table', 'data'),
[Input('dropdown_d', 'value'),
])
def update_table(selected_value):
df = pd.read_csv(data, header=0, encoding = 'utf8')
df_updated = df[df["district"] == selected_value]
columns = [{'name': i, 'id': i} for i in df_updated.columns]
data = df.to_dict('records')
return columns, data
if __name__ == "__main__":
app.run_server(debug=True, port=8055)
This is the farthest i can get. The code above is only trying to update the data-table from 1 dropdown value, but my goal is to update by 2 dropdown values.
any help is very much appreciated.
in case the data file is needed, here is the link to the data.
Here is the snippet of the working code, I have added comments for clarification,
import pandas as pd
import dash
import dash_core_components as dcc
import dash_html_components as html
import dash_table as dt
from dash.dependencies import Input, Output, State
df = pd.read_csv("https://elartedm.com/wp-content/uploads/2020/03/data_hk.csv", header=0, encoding = 'utf8')
app = dash.Dash()
application = app.server
dropdown = html.Div([
html.Label('district'),
dcc.Dropdown(id='dropdown_d1', options=[{'label': i, 'value': i} for i in df["District"].unique()], value=None),
html.Label('address'),
dcc.Dropdown(id='dropdown_d2', options=[], value=None)
])
#its better to have a Div here so that you can update the entire div in the callback and add the necessary properties in the callback
final_table = html.Div(id="final_table")
app.layout = html.Div([dropdown, final_table])
#callback to update second dropdown based on first dropdown
#This callback is used to update the second dropdown based on the value selected in the first dropdown so that its dynamically updated (this is a good practice rather than having a static list of options).
@app.callback(Output('dropdown_d2', 'options'),
[
Input('dropdown_d1', 'value'),
])
def update_dropdown_2(d1):
print(d1)
if(d1 != None):
df_filtered = df[(df["District"]==d1)]
return [{'label': i, 'value': i} for i in df_filtered["Address"].unique()]
else:
return []
#this callback to update the final table should be based on both the input dropdown values, so the input parameters are two dropdown_d1, dropdown_d2
#based on these values filter the dataframe and update the table
#since dataframe is a global declaration you don't need to again consume it here.
@app.callback(Output('final_table', 'children'),
[
Input('dropdown_d1', 'value'),
Input('dropdown_d2', 'value'),
])
def update_table(d1, d2):
if(d1 != None and d2 != None):
df_filtered = df[(df["District"]==d1) & (df["Address"]==d2)]
return [dt.DataTable(
id='table',
columns=[{"name": i, "id": i} for i in df_filtered.columns],
data=df_filtered.to_dict('records'),
)]
else:
print("none")
return []
if __name__ == "__main__":
app.run_server(debug=True, port=8055)
Hope it helps.
