如何在Python中通过绘图从破折号的下拉列表中选择数据集列?
我希望能得到一些关于在Python中使用Dash by Plotly创建仪表板的指导。虽然网上有很多文档和论坛帖子,但我觉得它们假设了我可能缺少的一些知识,特别是在正确使用回调实现交互方面 我试图实现的是一个仪表板,它将允许我:如何在Python中通过绘图从破折号的下拉列表中选择数据集列?,python,callback,dashboard,plotly-dash,Python,Callback,Dashboard,Plotly Dash,我希望能得到一些关于在Python中使用Dash by Plotly创建仪表板的指导。虽然网上有很多文档和论坛帖子,但我觉得它们假设了我可能缺少的一些知识,特别是在正确使用回调实现交互方面 我试图实现的是一个仪表板,它将允许我: 上载Excel文件 从Excel文件中选择一列 运行函数以处理该列中的数据 在表格中显示结果输出数据 我曾试图创建一个最小的工作示例,但一直在努力。以下是我迄今为止所做的工作: import base64 import io import pandas as pd im
import base64
import io
import pandas as pd
import dash
import dash_table
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output, State
## 1. Define overall dashboard layout
Dashboard = dash.Dash(__name__, external_stylesheets=['https://codepen.io/chriddyp/pen/bWLwgP.css'])
Dashboard.layout = html.Div([
html.H1('Dashboard Prototype', style={'width':'100%', 'textAlign': 'center'}),
dcc.Upload(
id = 'Dashboard_Input',
children = html.A('Select Files'),
style = {'width': '100%', 'height': '60px', 'lineHeight': '60px', 'borderWidth': '1px',
'borderStyle': 'dashed', 'borderRadius': '5px', 'textAlign': 'center', 'display': 'inline-block'},
multiple = True
),
html.Br(),
html.Div(id='Dashboard_Dropdown'),
html.Br(),
html.Div(id='Dashboard_Output')
])
## 2. Define functions to upload, process and present data
def selectData(contents, filename, date):
content_type, content_string = contents.split(',')
decoded = base64.b64decode(content_string)
try:
Raw_Data = pd.read_excel(io.BytesIO(decoded))
except Exception as e:
return html.Div(['There was an error processing this file.'])
Dropdown = html.Div([
html.H4 (('File Name: ', filename), style={'width':'100%', 'textAlign': 'center'}),
html.Br(),
dcc.Dropdown(
id = 'Dataset_and_Column',
options = [{'label': i, 'value': i} for i in Raw_Data.columns],
style = {'width': '100%', 'height': '60px', 'lineHeight': '60px', 'borderWidth': '1px',
'borderStyle': 'dashed', 'borderRadius': '5px', 'textAlign': 'center', 'display': 'inline-block'},
placeholder = 'Select Dataset Column'
),
html.Br(),
])
return Dropdown
def processData(Raw_Data, Column_Label):
# DO SOME PROCESSING THAT RESULTS IN 'TABLE':
Table = Table
HTML_Table = html.Div([
dash_table.DataTable(
data = Table.to_dict('records'),
columns = [{'name': i, 'id': i} for i in Table.columns],
style_cell = {'textAlign': 'center', 'width': '100px'},
editable = False,
style_header = {'fontWeight': 'bold', 'textAlign': 'center'},
style_table = {'maxHeight': '50ex', 'width': '100%'}
),
html.Hr()
])
return HTML_Table
## 4. Define callback functions
Dashboard.config.suppress_callback_exceptions = True
@Dashboard.callback(
Output('Dashboard_Dropdown', 'children'),
[Input('Dashboard_Input' , 'contents')],
[State('Dashboard_Input' , 'filename'), State('Dashboard_Input', 'last_modified')]
)
def createDropdown(list_of_contents, list_of_names, list_of_dates):
if list_of_contents is not None:
Dropdown = [selectData(c, n, d) for c, n, d in zip(list_of_contents, list_of_names, list_of_dates)]
return Dropdown
################################################################################
################################################################################
# THIS BIT DOESN'T WORK #
# Need to make this callback function take an input of Raw_Date and Column_Label (selected from the dropdown) to run the processData() function.
@Dashboard.callback(
Output('Dashboard_Output' , 'children'),
[Input('Dataset_and_Column', 'contents'), Input('Dataset_and_Column', 'value')],
)
def processSelectedColumn(contents, value):
# HTML_Table = processData(contents, value)
return value#HTML_Table
# ^^^^^^ Note that this allow 'value' to be printed on the dashboard but
# when the commented 'HTML_Table' bits are uncommented it fails
################################################################################
################################################################################
## 6. Run dashboard
if __name__ == '__main__':
Dashboard.run_server(debug=True)
这允许我选择一个Excel文件,然后打印从中创建的Pandas数据框的选定列,但我不确定如何将所有列连接在一起,以便在选定列上运行我的processData()
函数
关于我如何没有正确使用或连接回调、函数等的任何想法?您需要
processSelectedColumn
回调来接受下拉列表中的值作为输入。也可以/最好将上传的数据作为状态
而不是输入
。这将为您提供执行所需计算所需的值。回答:
下面是一些代码片段,用于从短划线中的下拉列表中选择给定的列
数据集房价
:
df=pd.read\u csv(r“housing\u price.csv”)
将列保存在变量中,比如说options
,以调用dash的html标记
options=[]
对于df.列中的列:
options.append({'label':'{}'。格式(col,col),'value':col})
为DEAFULT下拉列表编写html标记
:
`
写回电话:
@app.callback(
输出('my_label1','children'),
[输入('my_dropdown1','value')]
)
def update_下拉列表(值):
return“您已选择{}进行直方图绘制!”。格式(值)
注意:如果您想使用状态
在用户单击提交按钮后,按照下面的代码激活对所选列的调用。
激活基于状态的回调:
@app.callback(
Output('my_label1', 'children'),
[Input('submit-button', 'n_clicks')],
[State('my_dropdown1','value')]
)
def update_dropdown_state(n_clicks,value):
return 'You have chosen {} for histogram plot!'.format(value)
@app.callback(
Output('my_label1', 'children'),
[Input('submit-button', 'n_clicks')],
[State('my_dropdown1','value')]
)
def update_dropdown_state(n_clicks,value):
return 'You have chosen {} for histogram plot!'.format(value)