[Tutor] Doubt in list comprehension

[Peter Otten]

vinod bhaskaran wrote:

> Hi All,
> 
> I am a beginner programmer and i wrote a small program (as per a
> assignment i saw) as below:
> 
> newlist = []
> for a in range(2,5):
>   for b in range (0,3):
>     newlist.append([a])
>     a = a + 1
> print(newlist)
> 
> it gives the expected output as below:
> [[2], [3], [4], [3], [4], [5], [4], [5], [6]]
> 
> but when i try list comprehension i am not able to get it correct....can
> someone please suggest where the (a=a+1) should be placed in a list
> comprehension

You canot sneak a statement like

>     a = a + 1

into a list comprehension, you have to modify the expressions. Given

[[...] for a in range(2, 5) for b in range(3)]

what expression replacing the ... would give the expected result? 

Hint: it depends on both a and b.

Once you have figured it out you can try and reshuffle it a bit into

[[b] for a in range(2, 5) for b in range(...)]