How to delete the first row of a CSV file using python?

Question

I want to delete only the first row (not the headers) of a CSV using Python.

I have tried many solutions using the csv module or pandas but nothing have worked for me yet. All the solutions either printed out the csv and didn’t modify the original file.

And importantly, I do not want to print out or skip/ignore the first line, I want to delete it and save it to the original file, not creating another file.

Asked By: dismaaay

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Source

Answer 1

FILENAME = 'test.csv'
DELETE_LINE_NUMBER = 1

with open(FILENAME) as f:
    data = f.read().splitlines() # Read csv file
with open(FILENAME, 'w') as g:
    g.write('n'.join([data[:DELETE_LINE_NUMBER]] + data[DELETE_LINE_NUMBER+1:])) # Write to file

Original test.csv:

ID, Name
0, ABC
1, DEF
2, GHI
3, JKL
4, MNO

After run:

ID, Name
1, DEF
2, GHI
3, JKL
4, MNO

(deleted 0, ABC)

Answered By: The Thonnu

Answer 2

If your (CSV) file is small enough, read it into memory, remove the line and write it back.

No Pandas or even the csv module needed here.

# Read lines into list
with open("myfile.csv") as f:
    lines = list(f)

lines.pop(1)  # pop the second line out (assuming the zeroth line is headers)

# Write lines back into file
with open("myfile.csv", "w") as f:
    for line in lines:
        f.write(line)

If your file is larger, don’t read it all into memory, but filter it into a second file on the fly, then replace the first:

import os

with open("myfile.csv") as rf, open("myfile.csv.temp", "w") as wf:
    for i, line in enumerate(rf):
        if i != 1:  # Everything but the second line
            wf.write(line)

os.replace("myfile.csv.temp", "myfile.csv")

Answered By: AKX

Answer 3

You can try that. It works if the file isn’t too big

# Read the data
with open("your file.csv", "r") as f:
    data = f.read().split("n")

# Remove the 1st line
del data[1]

# Save the data
with open("your file.csv", "w") as f:
    f.write("n".join(data))

Answered By: Sisyffe

Answer 4

After reading the csv file as csv reader, next() will return each row in the file, so can be solved like this:

import csv
csv_file_name= '<your_file_name>.csv'

file = open(csv_file_name)
csvreader = csv.reader(file)

# store headers and rows
header = next(csvreader)

# ignore first row 
next(csvreader)

# store other rows
rows = []
for row in csvreader:
        rows.append(row)

file.close()

with open(csv_file_name, 'w', encoding='UTF8', newline='') as f:
    writer = csv.writer(f)

    # write the header
    writer.writerow(header)

    # write multiple rows
    writer.writerows(rows)

Answered By: AmrAnwar

How to delete the first row of a CSV file using python?

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