Example of a universal template for matplotlib to plot Gantt charts

# -*- coding: utf-8 -*-
 
from datetime import datetime
import sys
import numpy as np
import  as plt
import matplotlib.font_manager as font_manager
import  as mdates
import logging
from pylab import *
['-serif'] = ['SimHei']
 
class Gantt(object):
    #Color swatches: reference/
    RdYlGr = ['#d73027', '#f46d43', '#fdae61','#fee08b', '#ffffbf', '#d9ef8b','#a6d96a', '#66bd63', '#1a9850']
 
    POS_START = 1.0
    POS_STEP = 0.5
 
    def __init__(self, tasks):
        self._fig = (figsize=(15,10))
        self._ax = self._fig.add_axes([0.1, 0.1, .75, .5])
 
         = tasks[::-1]  # Reverse order
 
    def _format_date(self, date_string):
        try:
            date = (date_string, '%Y-%m-%d %H:%M:%S')  # Convert a date string to a datetime type
        except ValueError as err:
            ("String '{0}' can not be converted to datetime object: {1}"
                   .format(date_string, err))
            (-1)
        mpl_date = mdates.date2num(date)  # Get a date type timestamp
        return mpl_date
 
    def _plot_bars(self):
        i = 0
        for task in :
            start = self._format_date(task['start'])  # Get the timestamp of the task start time
            end = self._format_date(task['end'])      # Get the timestamp of the end time of the task
            bottom = (i * Gantt.POS_STEP) + Gantt.POS_START
            width = end - start    # Width of column
            self._ax.barh(bottom, width, left=start, height=0.3,align='center', label=task['label'],color = [i%len()])
            i += 1
 
    def _configure_yaxis(self):
        task_labels = [t['label'] for t in ]   # All the scale text labels
        pos = self._positions(len(task_labels))          # Vegetative scale values
        ylocs = self._ax.set_yticks(pos)                 # Setting the y-axis scale
        ylabels = self._ax.set_yticklabels(task_labels)  # Set y-axis scale labels
        (ylabels, size='medium')                 # Set y-axis scale label attribute (medium font)
 
    def _configure_xaxis(self):
        self._ax.xaxis_date()     # Using the timeline
        rule = (, interval=1)   # Generate time generator (1 value per week, starting on Sunday)
        loc = (rule)                         # Generate time scales
        formatter = ("%m/%d")               # Generate time format
 
        self._ax.xaxis.set_major_locator(loc)          # Setting the master scale
        self._ax.xaxis.set_major_formatter(formatter)  # Setting up the main scale label format
        xlabels = self._ax.get_xticklabels()           # Get the scale label object
        (xlabels, rotation=70, fontsize=10)    # Set the properties of the scale label object (30 degree rotation, font size 10)
 
    def _configure_figure(self):
        self._configure_xaxis()
        self._configure_yaxis()
 
        self._ax.grid(True, axis='x',color='gray')
        self._set_legend()
        self._fig.autofmt_xdate()
 
    def _set_legend(self):
        font = font_manager.FontProperties(size='small')
        self._ax.legend(loc='upper right', prop=font)
 
    def _positions(self, count):
        end = count * Gantt.POS_STEP + Gantt.POS_START
        pos = (Gantt.POS_START, end, Gantt.POS_STEP)
        return pos
    
    def show(self):
        self._plot_bars()
        self._configure_figure()
        ()

if __name__ == '__main__':
    TEST_DATA = (
                 { 'label': 'Project Research', 'start':'2019-02-01 12:00:00', 'end': '2019-03-15 18:00:00'},
                 { 'label': 'Project preparation', 'start':'2019-02-15 09:00:00', 'end': '2019-04-09 12:00:00'},
                 { 'label': 'Developing programs', 'start':'2019-04-10 12:00:00', 'end': '2019-05-30 18:00:00'},
                 { 'label': 'Project implementation', 'start':'2019-05-01 09:00:00', 'end': '2019-08-31 13:00:00'},
                 { 'label': 'Project training', 'start':'2019-07-01 09:00:00', 'end': '2019-09-21 13:00:00'},
                 { 'label': 'Project acceptance', 'start':'2019-09-22 09:00:00', 'end': '2019-10-22 13:00:00'},
                 { 'label': 'Project completion', 'start':'2019-10-23 09:00:00', 'end': '2019-11-23 13:00:00'},
                )
    
    gantt = Gantt(TEST_DATA)
    ('Project date')
    ('Project progress')
    ('Gantt chart of project progress')
    (figsize=(10,10),dpi=150)
    ()