One week equals $7$ days. The following program intends to read a floating$-$point value from input, convert the value from days to weeks, and output the quantity in weeks, but the code contains an error. Find and fix the error.

Ex: If the input is $1\mathrm{.}1,$ then the output is:

$0\mathrm{.}157$ weeks

$1$ # Modify the following code

$2$ length$\_$days $=$ input $()$

$3$ length$\_$weeks $=$ length$\_$days $\frac{?}{7}||$

$4$

$5$ print$($f$\text{'}$ length$\_$weeks: $\mathrm{.}3f$ weeks'$)$