在一个标题下按列附加到 csv 文件

Question

Coding in Python 2.7. I have a csv file already present called input.csv. In that file we have 3 headers — Filename, Category, Version — under which certain values already exist.

I want to know how I can reopen the csv file and input only one value multiple times under the "Version" column such that whatever was written under "Version" gets overwritten by the new input.

So suppose under the "Version" column I had 3 inputs in 3 rows:

VERSION
  55
  66
  88

It gets rewritten by my new input 10 so it will look like:

VERSION
  10
  10
  10

I know normally we input csv row-wise but this time around I just want to input column wise under that specific header "Version".

Answer 1

Solution 1:

With pandas , you can use:

import pandas as pd
df = pd.read_csv(file)
df['VERSION'] = 10
df.to_csv(file, index=False)

Solution 2: If there are multiple rows (and you only want first 3), then you can use:

df.loc[df.index < 3, ['VERSION']] = 10   

instead of:

df['VERSION'] = 10