concatenate two element of different list as 1 variable in python

Question

concatenate two elements as 1 element for example we are given two arrays a and b:

a=[1,2,3]
b=[4,5,6]

so what I want is an output as

14, 25, 36

What have you tried so far? – joshmeranda Apr 14 '22 at 19:56 — joshmeranda, Apr 14 '22 at 19:56
`list(10*aa + bb for aa, bb in zip(a, b))`. – hiro protagonist Apr 14 '22 at 19:57 — hiro protagonist, Apr 14 '22 at 19:57

score 3 · Accepted Answer · answered Apr 14 '22 at 19:58

3

If a and b are lists of integers, you could do the following:

c = [i * 10 + j for i, j in zip(a, b)]

If they are lists of strings, you could do the following:

c = [i + j for i, j in zip(a, b)]

answered Apr 14 '22 at 19:58

Michael Hodel

`map(lambda t: t[0]*10+t[1], zip(a,b))` – dawg Apr 14 '22 at 20:03
2

You wouldn't need `zip`: `map(lambda x, y: x*10 + y, a, b)`. – chepner Apr 14 '22 at 20:05

MeBex · Answer 2 · 2022-04-15T09:08:40.357

0

result = [int(f'{x}{y}') for x, y in zip(a, b)]

edited Apr 15 '22 at 09:08

answered Apr 14 '22 at 20:07

MeBex

For the given input, this is considerably slower than doing the math. – chepner Apr 14 '22 at 20:08
Yeah, doing math is more optimized than this ;) – MeBex Apr 14 '22 at 20:12
For a slight improvement: `int(f'{x}{y}')` is likely faster that str concat. (ref: [Why are f-strings faster than str() to parse values?](https://stackoverflow.com/q/56587807/15497888)) – Henry Ecker Apr 14 '22 at 21:16

2 Answers2