how to insert a column to a list of lists in python

Question

I have the following list (which is much larger in reality)

[(1, 2, 3),
 (1, 2, 3),
 (1, 2, 3)]

and would like to insert 2 columns to it so it results in

 [(c1, 1, c2, 2, 3),
  (c1, 1, c2, 2, 3),
  (c1, 1, c2, 2, 3)]

the best which I came up with is the following

mylist = [(1, 2, 3),(1, 2, 3),(1, 2, 3)]
mylist_new = []
for i in mylist:
    mylist_new.append(('c1', i[0], 'c2', i[1], i[2], i[3]))

any alternative suggestions on how to achieve this?

miindlek · Accepted Answer · 2015-08-23 18:33:13Z

4

You could use list comprehension.

mylist = [(1, 2, 3),(1, 2, 3),(1, 2, 3)]
mylist_new = [('c1', i, 'c2', j, k) for (i, j, k) in mylist]

answered Aug 23, 2015 at 18:33

miindlek

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