CODEWITHSUNDEEP
pythonbokeh
Alex Johnson
Alex Johnson

Reputation: 11

How do I extract data from Bokeh Point Draw Tool - generated html table for use in python

After much trouble, I was finally able to get Bokeh's point draw tool to work only to run into another problem: working with the data generated from this tool. The code below generates an interactive plot, and placing/moving points updates the table in real time. However, I cannot figure out how to extract the data in this table, for example, to a csv file. I have tried several strategies such as Excel>>Data>>From Web>>table and using the bs4 library but have had no luck. I do not know anything about html but upon opening the html file generated after using the point draw tool, the data for the initial points, and the points place later with the tool appear to be in separate places. This may be the cause of the problem. Basically, I just need to get the data from the html table into a format that I can easily utilize in python. Thank you for any help you can provide.

SOURCE CODE (python3.6.2)

    from datetime import date
    import time
    from random import randint
    
    from bokeh.io import output_file, show
    from bokeh.layouts import widgetbox
    from bokeh.models import ColumnDataSource, PointDrawTool
    from bokeh.models.widgets import DataTable, DateFormatter, TableColumn
    from bokeh.plotting import figure
    
    output_file("pointDrawResults.html")
    
    data = { "x": [5, 2, 8], "y": [5, 7, 8]}
    
    src = ColumnDataSource(data)
    
    columns = [
            TableColumn(field = "x", title = "xs"),
            TableColumn(field = "y", title = "ys"),
            ]
    data_table = DataTable(source = src, columns = columns, width = 400, height = 280)
    
    plot = figure(x_range = (0, 10), y_range = (0, 10), width = 400, height = 400, title = "Point Draw Tool")
    
    renderer = plot.circle("x", "y", size = 15, fill_color = "blue", fill_alpha = 0.8, source = src)
    
    draw_tool = PointDrawTool(renderers = [renderer], empty_value = 1)
    plot.add_tools(draw_tool)
    plot.toolbar.active_drag = draw_tool
    
    show(widgetbox(data_table))
    show(plot)

Upvotes: 0

Views: 1183

Answers (1)

Alex Johnson
Alex Johnson

Reputation: 11

I ended up just writing the below function to extract the new vertices generated from the point draw tool from the HTML file itself. A tip to anyone else in this predicament, make sure you increase the size of the displayed table such that all vertices are displayed at one time (no vertical scroll bar). Otherwise vertices are omitted from the HTML file and wont be found/extracted by the function.

import re

def extractHtmlVerts(self):
        indexList = []

        with open(self.vertexFileE.get(), 'r') as htmlFile:
            htmlCont = htmlFile.read()

        tokens = re.finditer("(\d+\.\d+)</span>", htmlCont)

        type = "x"
        for match in tokens:
            if type == "x":
                indexList.append(round(float(match.group(1))))
                type = "y"
            else:
                type = "x"

        return indexList

Upvotes: 1

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