Overwrite .csv file in directory

Question

I was wondering how I can overwrite an existing .csv file in the same file directory called test.csv

My following program opens the test.csv file it then appends some string names to it and is then called "main" dataframe. I was wondering how I can save "main" to the same directory as test.csv. Therefore replacing the old test.csv with the new one.

import pandas as pd

main=pd.read_csv('C:/Users/Jonas/Desktop/testfile/test.csv', header=None)

target_col = ['dog'] * main.shape[0]
target_col[0] = 'target'
main.insert(loc = 0, column = -1, value = target_col)
main.rename(columns = lambda x:x+1,inplace=True) #Reorients -1 to the origin
#How to rewrite test.csv?

Image showing the old test.csv file and the new "Final" dataframe: enter image description here

Thanks. Below shows the saved data error: enter image description here

How about *main.to_csv('C:/Users/Jonas/Desktop/testfile/test.csv')* ? — DarkKnight, Feb 02 '22 at 10:41
https://stackoverflow.com/questions/20845213/how-to-avoid-python-pandas-creating-an-index-in-a-saved-csv — S R Maiti, Feb 02 '22 at 12:50

score 1 · Answer 1 · answered Feb 02 '22 at 10:41

1

Use to_csv

main.to_csv('C:/Users/Jonas/Desktop/testfile/test.csv', header=None)

answered Feb 02 '22 at 10:41

Tobi208

1,306
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When I view my new data from excel It has another column going down 0, 1, 2, 3 rows. I've attached another image on the post showing this. I'm wondering how I can make python save the .csv file without this unnecessary column? Cheers. – Python_warrior Feb 02 '22 at 12:48
use "index=False" as another option after "header=None", see my answer and mark both answers as correct please. – Mattis Seehaus Feb 02 '22 at 12:51

score 1 · Accepted Answer · answered Feb 02 '22 at 12:53

1

 main.to_csv('C:/Users/Jonas/Desktop/testfile/test.csv', header=None, index=False)

answered Feb 02 '22 at 12:53

Mattis Seehaus

114
1
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Overwrite .csv file in directory

2 Answers2