如何使用Pandas将新工作表保存在现有的Excel文件中？

Question

我想使用Excel文件来存储用python制作的数据。我的问题是我无法将图纸添加到现有的excel文件中。在这里，我建议使用示例代码来解决此问题

import pandas as pd
import numpy as np

path = r"C:\Users\fedel\Desktop\excelData\PhD_data.xlsx"

x1 = np.random.randn(100, 2)
df1 = pd.DataFrame(x1)

x2 = np.random.randn(100, 2)
df2 = pd.DataFrame(x2)

writer = pd.ExcelWriter(path, engine = 'xlsxwriter')
df1.to_excel(writer, sheet_name = 'x1')
df2.to_excel(writer, sheet_name = 'x2')
writer.save()
writer.close()

此代码将两个DataFrame保存到两个表中，分别命名为“ x1”和“ x2”。如果创建两个新的DataFrame并尝试使用相同的代码添加两个新的工作表“
x3”和“ x4”，则原始数据将丢失。

import pandas as pd
import numpy as np

path = r"C:\Users\fedel\Desktop\excelData\PhD_data.xlsx"

x3 = np.random.randn(100, 2)
df3 = pd.DataFrame(x3)

x4 = np.random.randn(100, 2)
df4 = pd.DataFrame(x4)

writer = pd.ExcelWriter(path, engine = 'xlsxwriter')
df3.to_excel(writer, sheet_name = 'x3')
df4.to_excel(writer, sheet_name = 'x4')
writer.save()
writer.close()

我想要一个具有四张纸的Excel文件：“ x1”，“ x2”，“ x3”，“ x4”。我知道“ xlsxwriter”不是唯一的“引擎”，而是“
openpyxl”。我还看到已经有其他人对此问题进行了写作，但是我仍然不知道如何做到这一点。

这是从此链接获取的代码

import pandas
from openpyxl import load_workbook

book = load_workbook('Masterfile.xlsx')
writer = pandas.ExcelWriter('Masterfile.xlsx', engine='openpyxl') 
writer.book = book
writer.sheets = dict((ws.title, ws) for ws in book.worksheets)

data_filtered.to_excel(writer, "Main", cols=['Diff1', 'Diff2'])

writer.save()

他们说这行得通，但是很难弄清楚是怎么回事。我不了解在此上下文中的“ ws.title”，“ ws”和“ dict”是什么。

保存“ x1”和“ x2”，然后关闭文件，再次打开并添加“ x3”和“ x4”的最佳方法是什么？

Answer 1

谢谢。我相信，一个完整的示例可能会对遇到相同问题的其他人有所帮助：

import pandas as pd
import numpy as np

path = r"C:\Users\fedel\Desktop\excelData\PhD_data.xlsx"

x1 = np.random.randn(100, 2)
df1 = pd.DataFrame(x1)

x2 = np.random.randn(100, 2)
df2 = pd.DataFrame(x2)

writer = pd.ExcelWriter(path, engine = 'xlsxwriter')
df1.to_excel(writer, sheet_name = 'x1')
df2.to_excel(writer, sheet_name = 'x2')
writer.save()
writer.close()

根据我的理解，在这里我生成一个excel文件，无论它是通过“ xslxwriter”还是“ openpyxl”引擎生成的，都没有关系。

当我想写而不丢失原始数据时

import pandas as pd
import numpy as np
from openpyxl import load_workbook

path = r"C:\Users\fedel\Desktop\excelData\PhD_data.xlsx"

book = load_workbook(path)
writer = pd.ExcelWriter(path, engine = 'openpyxl')
writer.book = book

x3 = np.random.randn(100, 2)
df3 = pd.DataFrame(x3)

x4 = np.random.randn(100, 2)
df4 = pd.DataFrame(x4)

df3.to_excel(writer, sheet_name = 'x3')
df4.to_excel(writer, sheet_name = 'x4')
writer.save()
writer.close()

此代码可以完成工作！