Writing a Python list of lists to a csv file

I have a long list of lists of the following form —

a = [[1.2,'abc',3],[1.2,'werew',4],........,[1.4,'qew',2]]

i.e. the values in the list are of different types — float,int, strings.How do I write it into a csv file so that my output csv file looks like

1.2,abc,3
1.2,werew,4
.
.
.
1.4,qew,2