我想基于一个间隔更新我的Dash data_table。它将运行,但是没有任何更新。我认为这并不难,但我显然缺少一些东西。这是我所拥有的:
import dash
from dash.dependencies import Input, Output
import dash_core_components as dcc
import dash_html_components as html
import dash_table
import time
import pandas as pd
数据组件
def getData():
"""
Only can hit api every 6 seconds for 14 total items,
which is relevant towards the Dash interval
"""
df = pd.DataFrame()
for item in list:
data = *hit api*
df = df.append(data)
time.sleep(7)
return df
破折号组件
app = dash.Dash(__name__)
# passing in just column names to avoid needlessly hitting API
tblcols=[{'name': 'col1', 'id': 'col1'},
{'name': 'col2', 'id': 'col2'},
{'name': 'col3', 'id': 'col3'}
]
app.layout = html.Div([
html.H4('Dashboard Name'),
dcc.Interval('graph-update',interval = 500000, n_intervals = 0),
dash_table.DataTable(
id = 'table',
data = [{}],
columns=tblcols )])
@app.callback(
Output('table','data'),
[Input('graph-update', 'n_intervals')]
)
def updateTable(n):
"""
calling the get data function
"""
updated_data = getData()
return updated_data.to_dict('records')
if __name__ == '__main__':
app.run_server(debug=False)
同样,它将运行并返回我通过的列标题,但是当我看到更新已在控制台““ POST / _dash-update-component HTTP / 1.1”“中运行时,没有任何变化
答案 0 :(得分:0)
我认为问题在于您返回了一个空的dataframe
。这是因为您使用df.append(data)
而不是df = df.append(data)
这是一个简化且有效的代码(Dash v1.6.0):
import dash
import dash_core_components as dcc
import dash_html_components as html
import dash_table
import pandas as pd
import numpy as np
app = dash.Dash(__name__)
def getData():
df = pd.DataFrame()
for idx in range(10):
data = {'x': np.random.random(1)[0], 'y': np.random.random(1)[0]}
df = df.append(data, ignore_index=True)
return df.to_dict('records')
tblcols=[{'name': 'x', 'id': 'x'},
{'name': 'y', 'id': 'y'}, ]
app.layout = html.Div([
html.H4('Dashboard'),
dcc.Interval('graph-update', interval = 1000, n_intervals = 0),
dash_table.DataTable(
id = 'table',
data = getData(),
columns=tblcols)])
@app.callback(
dash.dependencies.Output('table','data'),
[dash.dependencies.Input('graph-update', 'n_intervals')])
def updateTable(n):
return getData()
if __name__ == '__main__':
app.run_server(debug=False)