Python openpyxl Excel绘制柱形图

这是一份openpyxl的使用指南。

大体内容翻译自官网 https://openpyxl.readthedocs.io/en/stable/charts/bar.html#vertical-horizontal-and-stacked-bar-charts

本文在官网基础上会有一些改动。代码请参考 https://github.com/RustFisher/python-playground

本文链接 https://rustfisher.com/2019/11/14/Python/Python-openpyxl_charts_Bar_and_Column/

柱形图

数据会被绘制成垂直，水平或者是层叠效果的柱形图。

注意：

• 接下来的设置会影响到不同类型的图表。
• 设置类别可以控制柱形图是垂直或是水平。
• 使用层叠图形时，需要设置overlap成100。
• 如果柱形是水平的，x和y坐标会对调过来。

2D图表

示例代码如下，根据给定的数据绘制了4张图表。

from openpyxl import Workbook
from openpyxl.chart import BarChart, Series, Reference

def bar_chart_demo():
    wb = Workbook(write_only=True)
    ws = wb.create_sheet()

    rows = [
        ('Number', 'Batch 1', 'Batch 2'),
        (2, 10, 30),
        (3, 40, 60),
        (4, 50, 70),
        (5, 20, 10),
        (6, 10, 40),
        (7, 50, 30),
    ]

    for row in rows:
        ws.append(row)

    chart1 = BarChart()
    chart1.type = "col"
    chart1.style = 10
    chart1.title = "Bar Chart"
    chart1.y_axis.title = 'Test number'
    chart1.x_axis.title = 'Sample length (mm)'

    data = Reference(ws, min_col=2, min_row=1, max_row=7, max_col=3)
    cats = Reference(ws, min_col=1, min_row=2, max_row=7)
    chart1.add_data(data, titles_from_data=True)
    chart1.set_categories(cats)
    chart1.shape = 4
    ws.add_chart(chart1, "A10")

    from copy import deepcopy

    chart2 = deepcopy(chart1)
    chart2.style = 11
    chart2.type = "bar"
    chart2.title = "Horizontal Bar Chart"

    ws.add_chart(chart2, "I10")

    chart3 = deepcopy(chart1)
    chart3.type = "col"
    chart3.style = 12
    chart3.grouping = "stacked"
    chart3.overlap = 100
    chart3.title = 'Stacked Chart'

    ws.add_chart(chart3, "A27")

    chart4 = deepcopy(chart1)
    chart4.type = "bar"
    chart4.style = 13
    chart4.grouping = "percentStacked"
    chart4.overlap = 100
    chart4.title = 'Percent Stacked Chart'

    ws.add_chart(chart4, "I27")

    wb.save("out/bar.xlsx")

if __name__ == '__main__':
    bar_chart_demo()

译者注：这里调整了图表在excel中的位置，原文是在G列，即G10和G27，这里改为了I列。代码格式也有微调。

我们需要生成图表的时候，Excel会要我们先选定数据范围（来源）。在代码中用Reference来指定数据来源范围。

3D图表

绘制3D图表，使用BarChart3D。

def bar_3d():
    wb = Workbook()
    ws = wb.active

    rows = [
        (None, 2013, 2014),
        ("Apples", 5, 4),
        ("Oranges", 6, 2),
        ("Pears", 8, 3)
    ]

    for row in rows:
        ws.append(row)

    data = Reference(ws, min_col=2, min_row=1, max_col=3, max_row=4)
    titles = Reference(ws, min_col=1, min_row=2, max_row=4)
    chart = BarChart3D()
    chart.title = "3D Bar Chart"
    chart.add_data(data=data, titles_from_data=True)
    chart.set_categories(titles)

    ws.add_chart(chart, "E5")
    wb.save("out/bar3d.xlsx")

创建好的图表用WPS打开发现是2D的。用Office Excel打开是3D的。