Write text with comma into a cell in CSV file using python

Each line of the file is a data record. Each record consists of one or more fields, separated by commas.

The basic idea of separating fields with a comma is clear, but that idea gets complicated when the field data may also contain commas or even embedded line-breaks.

CSV implementations may not handle such field data, or they may use quotation marks to surround the field. -- From https://en.wikipedia.org/wiki/Comma-separated_values

So you can use quotation marks to surround the each field text.

Suppose the input is ['1,2,3', 'Hello'], the output to CSV should be "1,2,3", "Hello", you can use codes below to achieve this.

>>> ",".join('"{0}"'.format(s) for s in ['1,2,3', 'Hello'])
'"1,2,3","Hello"'

But you will encounter problems when there are some special symbols such as ", \n and etc in text.

The python csv library has handled all the edge cases for you.

Write to file

Can use @Dominic Rodger answer.

>>> import csv
>>> spamWriter = csv.writer(open('eggs.csv', 'wb'))
>>> spamWriter.writerow(['Spam', 'Lovely, Spam'])

Write to string

From https://stackoverflow.com/a/9157370/5238892.

In Python 3:

>>> import io
>>> import csv
>>> output = io.StringIO()
>>> csvdata = [1,2,'a','He said "what do you mean?"',"Whoa!\nNewlines!"]
>>> writer = csv.writer(output, quoting=csv.QUOTE_NONNUMERIC)
>>> writer.writerow(csvdata)
59
>>> output.getvalue()
'1,2,"a","He said ""what do you mean?""","Whoa!\nNewlines!"\r\n'

Some details need to be changed a bit for Python 2:

>>> output = io.BytesIO()
>>> writer = csv.writer(output)
>>> writer.writerow(csvdata)
57L
>>> output.getvalue()
'1,2,a,"He said ""what do you mean?""","Whoa!\nNewlines!"\r\n'