Bokeh DataTable在选择调用时返回行和列

Question

使用onchange回调，我可以在Bokeh中获得DataTable中所选内容的数值行索引。 是否可以： a） 获取列索引 b） 获取索引的值（列和行标题）

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]))

这将给出以下可以返回行和所选内容内的值的命令。如果我总是希望返回一个列，这是理想的。然而，选择界面（虚线）似乎表明特定列是已知的，而不仅仅是行。 如果无法获得所选列，是否可以同时使用行索引和单元格值进行查找？在

Local Server Output & Table

Answer 1

下面的代码使用JS回调来显示行和列索引以及单元格内容。第二个Python回调是重置索引的技巧，以便可以检测到对同一行的单击（用bokehv1.0.4测试）。使用bokeh serve show app.py运行

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：