Python – How to use list inferences to replace commas with escaped commas in lists containing strings and numbers

I

have a tuple that contains string and numeric elements, and I tried to replace the comma present in one of the tuple elements with an escaped comma, for example the input looks like this

('', 'i_like_cats', 'I like, cookies', 10319708L, "* / Item ID='10319708'", 'i_wish_was_an_oscar_meyer_weiner',
0.101021321)

The output I want is

('', 'i_like_cats', 'I like\, cookies', 10319708L, "* / Item ID='10319708'", 'i_wish_was_an_oscar_meyer_weiner',
0.101021321)

What I’d like to do is replace the after like , since I’m outputting the content to a csv file, so when the next step in the pipeline reads the file, it splits the file at the comma between ‘like’ and ‘cookies’, even if I don’t want it. I can’t modify the code for the downstream part of the pipeline, so I can’t switch to a file like a semicolon or tab-delimited file, nor can I change it.

What I’m trying to do is use list understanding to solve this problem as shown below

line = map(lambda x: str.replace(x, '"', '\"'), line)

But this generates a type error indicating that the replacement requires a string object, but it received a long integer.

The only solution I can think of is to break the tuple into separate elements, modify the element that contains the comma, and then build a new tuple and append each element back, but there seems to be a way to do this in a more pythonic way.

Thanks!

I think list understanding works best for applying rules for each element; If you know which string to change, why can’t you just change that string?

If you want to change all commas to escape commas, might as well try this:

strtuple = ('', 'i_like_cats', 'I like, cookies', 10319708, "* / Item ID='10319708'", 'i_wish_was_an_oscar_meyer_weiner',
0.101021321)
converted_strlist = [i.replace(',', '\\,') if isinstance(i, str) else i for i in strtuple]