Write each item in a list into individual cells in csv python

Write each item in a list into individual cells in csv python

I want to take all the data in separate csv files and merge the data into
one big csv file that has the same formatting.
I am able to extract all the data and organize them into lists of lists,
but when I write to the main csv file it writes the data into one cell as
opposed to each element being in its own cell. And when opening them in
excel each list is in one cell as oppose to having each element of the
list being in its own individual cell.
So my question is how would I output individual elements in their own
cells into a csv file.
Thanks in advance.