[Tutor] Python program to remove first four even numbers from a list

[Manprit Singh]

Dear sir,

By writing this :
lst[:] = remove4even(lst)   # here i am modify the existing list lst

But by doing this

lst = remove4even(lst)     #  Now variable lst is reassigned, so it is a
different object

Regards
Manprit Singh

On Sun, Oct 17, 2021 at 1:49 PM Alan Gauld via Tutor <tutor at python.org>
wrote:

> On 17/10/2021 02:09, Manprit Singh wrote:
> > Dear Sir,
> >
> > So finally I came up with this solution:
> > def remove4even(seq):
> >     evencnt = 0
> >     lx = []
> >     for ele in seq:
> >         if evencnt > 3 or ele%2 != 0:
> >             lx.append(ele)
> >         else:
> >             evencnt += 1
> >     return lx
> >
> > lst =[3, 6, 7, 5, 4, 7, 8, 9, 1, 8, 2, 5, 4]
> > print(remove4even(lst))       # gives the right answer as
> >
> > [3, 7, 5, 7, 9, 1, 2, 5, 4]
> >
> > and to bring these changes in the existing  same list(lst), just doing
> this:
> > lst =[3, 6, 7, 5, 4, 7, 8, 9, 1, 8, 2, 5, 4]
> > lst[:] = remove4even(lst)
>
> You don't need the slice. Just assign the new list to lst
>
> lst = remove4even(lst)
>
> > Is there any other  good way to achieve this ? I don't like changing
> > mutable data inside functions.
> What you have done is fine.
>
> --
> Alan G
> Author of the Learn to Program web site
> http://www.alan-g.me.uk/
> http://www.amazon.com/author/alan_gauld
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>
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