将新工作表添加到现有的excel文件并绘制数据图形

Question

I am looking to add a new sheet to an excel file by exporting a pandas dataframe and graph the data using openpyxl. Currently I can add a new sheet and insert the pandas dataframe but not the graph of the data.

Currently my code looks like this.

import pandas
import openpyxl
from openpyxl.chart import LineChart, Reference

fileSavePath = 'C:/Users/PATH'
filename = "Existing Excel File"

lst1 = [1, 2, 3, 4, 5, 6, 7, 8, 9]
lst2 = [0, 5, 2, 8, 15, 7, 10, 4, 0]

df = pandas.DataFrame({'First Column': lst1, 'Second Column': lst2})

book = openpyxl.load_workbook(fileSavePath + filename + '.xlsx')
with pandas.ExcelWriter(fileSavePath + filename + '.xlsx', engine='openpyxl') as writer:
    writer.book = book
    writer.sheets = dict((ws.title, ws) for ws in book.worksheets)
    df.to_excel(writer, 'new_sheet', index=False)

wb = openpyxl.Workbook()
sheet = wb.active
values = Reference(sheet, min_col=1, min_row=1,
                   max_col=1, max_row=len(lst1))
chart = LineChart()
chart.add_data(values)
chart.title = " LINE-CHART "
chart.x_axis.title = " X-AXIS "
chart.y_axis.title = " Y-AXIS "
sheet.add_chart(chart, "E2")
writer.save()
writer.close()

Currently there is no error and the dataframe writes in but the graph does not appear in the newly added sheet.

Answer 1

This code will successfully add a new sheet and graph the data.

import pandas
from openpyxl.chart import LineChart, Reference
from openpyxl.utils.dataframe import dataframe_to_rows
from openpyxl import load_workbook

lst1 = [1, 2, 3, 4, 5, 6, 7, 8, 9]
lst2 = [0, 5, 2, 8, 15, 7, 10, 4, 0]
df = pandas.DataFrame({'First Column': lst1, 'Second Column': lst2})
fileSavePath = 'C:/Users/PathExample'
filename = "filename"
newSheetName = 'newSheet'
sheet = newSheetName
# load in existing workbook
wb = load_workbook(fileSavePath + filename + '.xlsx')
# create new sheet with name assigned by title
wb.create_sheet(newSheetName)
# find which sheet is the new sheet
newSheetIndex = len(wb.sheetnames) - 1
# set the newest sheet as the active sheet
wb.active = newSheetIndex
worksheet = wb.active

# Insert Dataframe
for r in dataframe_to_rows(df, index=False, header=True):
    worksheet.append(r)

#Graph data
chart = LineChart()
data = Reference(worksheet, range_string=f'{sheet}!B2:B10')
category = Reference(worksheet, range_string=f'{sheet}!A2:A10')
chart.add_data(data, titles_from_data=True)
chart.set_categories(category)
worksheet.add_chart(chart, 'D3')
wb.save(fileSavePath + filename + '.xlsx')

The issue appears to be in setting the active sheet. The previous code added the sheets but kept graphing the "active sheet" which is why the graph did not appear on the other sheets. Openpyxl uses a list to keep track of the excel sheets so to manipulate a desired sheet you need to set that index number as the active sheet (wb.active).