- A+

Category：Languages

For

`A=[1,2,3]`

I would like to get

`B=['r1','t1','r2','t2','r3','t3']`

I know it is easy to get `['r1','r2','r3']`

by

`['r'+str(k) for k in A]`

How could I get B by one line loop as I showed above?

Many thanks.

Use a nested list comprehension:

`A=[1,2,3] B = [prefix + str(a) for a in A for prefix in 'rt'] `