PYTHON > Rearrange item data ("date") within .csv file

Question

Source csv:

column a, column b, 2021-01-09, column d
column a, column b, 2021-01-10, column d
column a, column b, 2021-01-11, column d

Desired output:

09/01/2021, column a, column b, column d
10/01/2021, column a, column b, column d
11/01/2021, column a, column b, column d

What is the best method to achieve this, pythonically?
Thanks in advance!

score 1 · Accepted Answer · answered Jan 09 '21 at 13:33

1

Assuming your row from the csv is like

row = ["column a", "column b", "2021-01-09", "column d"]

you can do something like

import datetime

row.sort()
row[0] = datetime.datetime.strptime(row[0], '%Y-%m-%d').strftime('%d/%m/%y')

gives row as

>>> row
['09/01/21', 'column a', 'column b', 'column d']

answered Jan 09 '21 at 13:33

Jarvis

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1

Thanks @Jarvis for your concise answer! – shongyang low Jan 09 '21 at 13:43

score 1 · Answer 2 · answered Jan 09 '21 at 13:36

One way with pandas to achieve that as you already have answer's using csv.DictWriter

import pandas as pd
df = pd.read_csv('source.csv',names=["ColA", "ColB", "Date", "ColD"])
df['Date'] = pd.to_datetime(df['Date'].str.strip(), format='%Y-%m-%d').dt.strftime('%d/%m/%Y')
new_df = df[['Date', 'ColA', 'ColB', 'ColD']]
print(new_df)

Output:

         Date      ColA       ColB       ColD
0  09/01/2021  column a   column b   column d
1  10/01/2021  column a   column b   column d
2  11/01/2021  column a   column b   column d

glad it helps you somehow :) – A l w a y s S u n n y Jan 09 '21 at 14:14 — A l w a y s S u n n y, Jan 09 '21 at 14:14

score 0 · Answer 3 · answered Jan 09 '21 at 13:31

Reordering, as per:
Python - re-ordering columns in a csv

import csv

with open('file.csv', 'r') as infile, open('reordered.csv', 'a') as outfile:
    fieldnames = ['column c', 'column a', 'column b', 'column d']
    writer = csv.DictWriter(outfile, fieldnames=fieldnames)
    writer.writeheader()
    for row in csv.DictReader(infile):
        writer.writerow(row)

Adding dates:
In python how to change date format in a csv?

import datetime

with open("reordered.csv", 'r') as csvfile, open('file.csv', 'w') as temp_file:

    for line in csvfile.readlines():
        # Fetch all dates in the csv
        dates = line.split(',')

        # Extract date, month and year
        yr, mon, dt = dates[0].split('-')

        # Convert the second date and replace
        dates[0] = datetime.datetime.strptime(dates[0], '%y-%b-%d').strftime('%d/%b/%Y')

        # Write date to temp file
        temp_file.write(','.join(dates))

PYTHON > Rearrange item data ("date") within .csv file

3 Answers3