$($Python Problem$)6\mathrm{.}12\mathrm{.}1$: Functions arguments

vals$\_$to$\_$update is read from input. shift$\_$left$()$ has one parameter list$\_$to$\_$modify, and shifts list$\_$to$\_$modify left. Call shift$\_$left$()$ with a copy of the list vals$\_$to$\_$update as the argument to avoid modifying vals$\_$to$\_$update.

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Ex: If the input is:

Rub$-$a$-$dub$-$dub, three men in a tub

then the output is:

Shifted left: $[\text{'}$three$\text{'},$ 'men', $\text{'}$in$\text{'},\text{'}$a$\text{'},$ 'tub', 'Rub$-$a$-$dub$-$dub,$\text{'}]$

Original: $[\text{'}$Rub$-$a$-$dub$-$dub,$\text{'},$ 'three', 'men', $\text{'}$in$\text{'},\text{'}$a$\text{'},$ 'tub'$]$