I want to count the elements of a python list that is within a dataframe, and for the output to be a column in the dataframe. How do I do that?

Question

So, I have a data-frame that looks kind of like this: | column_1 | column 2 | | 0. | [a, \'b\', \'c\'] | | 1 | [\'z\', \'y\'] | | 2