How do I write to a .csv file with python

Question

I am writing a simple script with Python3.6 and am using the csv module to create a csv file. My code is attached below, and is a carbon copy of multiple examples I have found online, but when I run the code, I get the error message TypeError: a bytes-like object is required, not a 'str'.

import csv
File_Name = Test.csv
with open(File_Name, 'wb') as csvfile:
   filewriter = csv.writer(csvfile,delimiter=',')
   filewriter = writerow(['Paul','Mary'])

where does writerow come from? You are overriding filewriter — Oluwafemi Sule
– Oluwafemi Sule, Commented Sep 13, 2017 at 20:37
In Python 3.x the proper way to open the csv file for writing is open(open(File_Name, 'w', newline='') as csvfile: as shown in the examples in the documentation.. You also need to use filewriter.writerow(['Paul','Mary']). — martineau
– martineau, Commented Sep 13, 2017 at 20:41

Mark Tolonen · Accepted Answer · 2017-09-13 20:50:12Z

3

The csvwriter instance shouldn't be reassigned to. It should be used to write the rows.

In python 3, you should open the file in write only mode with newline='' per documentation.

import csv

filename = 'Test.csv'

with open(filename, 'w', newline='') as csvfile:
   file_writer = csv.writer(csvfile,delimiter=',')
   file_writer.writerow(['Paul','Mary'])

edited Sep 13, 2017 at 20:50

Mark Tolonen

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answered Sep 13, 2017 at 20:40

Oluwafemi Sule

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Comments

PRMoureu · Accepted Answer · 2017-09-13 20:35:54Z

2

If you don't need the binary mode, you can use this :

with open(File_Name, 'w') as csvfile:
   filewriter = csv.writer(csvfile,delimiter=',')
   filewriter.writerow(['Paul','Mary'])

Check the table here to see details about the different modes available.

edited Sep 13, 2017 at 20:35

answered Sep 13, 2017 at 20:29

PRMoureu

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Comments

sgetachew · Accepted Answer · 2017-09-13 20:52:39Z

2

You have to change from 'wb' to 'w' and file name should be in quotation("Test.csv" or 'Test.csv') see below

import csv
File_Name = "Test.csv"
with open(File_Name, 'w') as csvfile:
    filewriter = csv.writer(csvfile,delimiter=',')
    filewriter.writerow(['Paul','Mary'])

answered Sep 13, 2017 at 20:52

sgetachew

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Comments

Oleh Rybalchenko · Accepted Answer · 2017-09-13 20:46:47Z

1

The thing is that you are opened file in a binary mode

with open(File_Name, 'wb') as csvfile:

This means that all data read from the file is returned as bytes objects, not str. If you don't need it, try:

with open(File_Name, 'w') as csvfile:

Also you should use writerow method of the csvwriter instead of reassign it:

file_writer.writerow(['Paul','Mary'])

edited Sep 13, 2017 at 20:46

answered Sep 13, 2017 at 20:30

Oleh Rybalchenko

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