散景数据表-返回选择回调的行和列

小编典典

散景数据表-返回选择回调的行和列

python

使用on_change回调，我可以在Bokeh中获取DataTable中所选内容的数字行索引。是否可以：a）获取列索引b）获取索引值（列标题和行标题）

示例代码：

from bokeh.io import curdoc
from bokeh.layouts import row, column
import pandas as pd
from bokeh.models import ColumnDataSource, ColorBar, DataTable, DateFormatter, TableColumn, HoverTool, Spacer, DatetimeTickFormatter

'''
Pandas
'''

df = pd.DataFrame(data = {'Apples': [5,10], 'Bananas': [16,15], 'Oranges': [6,4]})
df.rename(index={0:'A',1:'B'}, inplace=True)

'''
BOKEH
'''

sourceTableSummary = ColumnDataSource(df)
Columns = [TableColumn(field=colIndex, title=colIndex) for colIndex in df.columns] 
data_table = DataTable(columns=Columns, source=sourceTableSummary, index_position = 0, width = 1900, height = 200, fit_columns=False)

'''
Funcs
'''

def return_value(attr, old, new):
    selectionRowIndex=sourceTableSummary.selected.indices[0]
    print("Selected Row Index ", str(selectionRowIndex))
    selectionValue=sourceTableSummary.data['Apples'][selectionRowIndex]
    print("Selected value for Apples ", str(selectionValue))
    # selectionColumnIndex?
    # selectionRowHeader?
    # selectionColumnHeader?


sourceTableSummary.on_change('selected', return_value)

curdoc().add_root(column(children=[data_table]))

这给出了以下内容，它们可以返回行以及选择中的值。如果我总是希望返回单个列，则这是理想的。但是，选择UI（虚线）似乎表明特定的列是已知的，而不仅仅是行。如果无法获得选定的列，我可以同时使用行索引和单元格值来查找它吗？

本地服务器输出和表

阅读 259

2021-01-20

共1个答案

小编典典

以下代码使用JS回调显示行索引和列索引以及单元格内容。第二个Python回调是重设索引的技巧，以便可以检测到对同一行的单击（已使用Bokeh
v1.0.4进行了测试）。与运行bokeh serve --show app.py

from random import randint
from datetime import date
from bokeh.models import ColumnDataSource, TableColumn, DateFormatter, DataTable, CustomJS
from bokeh.layouts import column
from bokeh.models.widgets import TextInput
from bokeh.plotting import curdoc

source = ColumnDataSource(dict(dates = [date(2014, 3, i + 1) for i in range(10)], downloads = [randint(0, 100) for i in range(10)]))
columns = [TableColumn(field = "dates", title = "Date", formatter = DateFormatter()), TableColumn(field = "downloads", title = "Downloads")]
data_table = DataTable(source = source, columns = columns, width = 400, height = 280, editable = True, reorderable = False)

text_row = TextInput(value = None, title = "Row index:", width = 420)
text_column = TextInput(value = None, title = "Column Index:", width = 420)
text_date = TextInput(value = None, title = "Date:", width = 420)
text_downloads = TextInput(value = None, title = "Downloads:", width = 420)
test_cell = TextInput(value = None, title = "Cell Contents:", width = 420)

source_code = """
var grid = document.getElementsByClassName('grid-canvas')[0].children;
var row, column = '';

for (var i = 0,max = grid.length; i < max; i++){
    if (grid[i].outerHTML.includes('active')){
        row = i;
        for (var j = 0, jmax = grid[i].children.length; j < jmax; j++)
            if(grid[i].children[j].outerHTML.includes('active')) 
                { column = j }
    }
}
text_row.value = String(row);
text_column.value = String(column);
text_date.value = String(new Date(source.data['dates'][row]));
text_downloads.value = String(source.data['downloads'][row]); 
test_cell.value = column == 1 ? text_date.value : text_downloads.value; """

def py_callback(attr, old, new):
    source.selected.update(indices = [])

source.selected.on_change('indices', py_callback)
callback = CustomJS(args = dict(source = source, text_row = text_row, text_column = text_column, text_date = text_date, text_downloads = text_downloads, test_cell = test_cell), code = source_code)
source.selected.js_on_change('indices', callback)
curdoc().add_root(column(data_table, text_row, text_column, text_date, text_downloads, test_cell))

结果：

2021-01-20