How to append a pandas dataframe to an excel sheet

1
votes

Hi i have seen solutions to more complicated problems but am trying to do the following:

Append a dataframe to an excel table. I have an excel file which contains data like:

# Create Initial Excel 
data = [['tom', 10,1,'a'], ['matt', 15,5,'b'],['nick', 18,2,'b'],['luke', 12,6,'b'],['geoff', 20,10,'a']]

# Create the pandas DataFrame 
df = pd.DataFrame(data, columns = ['Name', 'Attempts','Score','Category']) 
df
    Name    Attempts    Score   Category
0   tom     10             1    a
1   matt    15             5    b
2   nick    18             2    b
3   luke    12             6    b
4   geoff   20             10   a

df.to_excel('Excel.xlsx',index=False)

Each week i get new data in the form of:

  #New Dataframe
    data2 = [['mick', 10,1,'a'], ['matt', 15,5,'b'],['jim', 18,2,'b'],['mark', 12,6,'b'],['geoff', 20,10,'a']]
    df2 = pd.DataFrame(data2, columns = ['Name', 'Attempts','Score','Category']) 
    df2
        Name    Attempts    Score   Category
    0   mick    10             1    a
    1   matt    15             5    b
    2   jim     18             2    b
    3   mark    12             6    b
    4   geoff   20            10    a

I have tried the following to append the new data underneath the spreadsheet data:

#Append DF2

with pd.ExcelWriter('Excel.xlsx',
                    mode='a') as writer:
    df2.to_excel(writer,'Sheet1',index=False,header=False)

But it has appended to a new sheet?

I am just hoping to add to my excel so that it appears:

Name    Attempts    Score   Category
0   tom     10             1    a
1   matt    15             5    b
2   nick    18             2    b
3   luke    12             6    b
4   geoff   20             10   a
0   tom     10             1    a
1   matt    15             5    b
2   nick    18             2    b
3   luke    12             6    b
4   geoff   20             10   a
2
pythonexcelpandas

2 Answers

2
votes

I found my answer here append dataframe to excel with pandas and the specifics for my question

from openpyxl import load_workbook

path = "Excel.xlsx"
book = load_workbook(path)
writer = pandas.ExcelWriter("Excel.xlsx", engine='openpyxl')
writer.book = book
writer.sheets = {ws.title: ws for ws in book.worksheets}


df2.to_excel(writer, startrow=writer.sheets['Sheet1'].max_row, index = False,header= False)

writer.save()
0
votes

Here an approach you can try, something similar was mentioned in this answer. What I suggest is that first concatenate your 2 data-frames then write to the Excel file, instead of trying to merge the Excel files.

import pandas as pd

# Create Initial Excel 
data = [['tom', 10,1,'a'], ['matt', 15,5,'b'],['nick', 18,2,'b'],['luke', 12,6,'b'],['geoff', 20,10,'a']]

# Create the pandas DataFrame 
df = pd.DataFrame(data, columns = ['Name', 'Attempts','Score','Category']) 

#New Dataframe
data2 = [['mick', 10,1,'a'], ['matt', 15,5,'b'],['jim', 18,2,'b'],['mark', 12,6,'b'],['geoff', 20,10,'a']]
df2 = pd.DataFrame(data2, columns = ['Name', 'Attempts','Score','Category']) 

# Prepare a list of the dataframes, needed for the concat method
all_df = [df, df2]

out_df = pd.concat(all_df).reset_index(drop=True)

# Write concatenated dataframes to Excel
out_df.to_excel("Combined.xlsx", index=False)