Python zip() behavior in bash?

code

[tmp]$ echo "A" > test_a 
[tmp]$ echo "B" >> test_a 
[tmp]$ echo "1" > test_b
[tmp]$ echo "2" >> test_b
[tmp]$ cat test_a
A
B
[tmp]$ cat test_b
1
2
[tmp]$ paste test_a test_b > test_c
[tmp]$ cat test_c
A   1
B   2

Pure bash:

liori@marvin:~$ zip34() { while read word3 <&3; do read word4 <&4 ; echo $word3 $word4 ; done }
liori@marvin:~$ zip34 3<a 4<b
alpha one
beta two
gamma three
delta four
epsilon five
liori@marvin:~$

(old answer) Look at join.

liori:~% cat a
alpha
beta
gamma
delta
epsilon
liori:~% cat b
one
two
three
four
five
liori:~% join =(cat -n a) =(cat -n b)
1 alpha one
2 beta two
3 gamma three
4 delta four
5 epsilon five

(assuming you've got the =() operator like in zsh, otherwise it's more complicated).