I have this program already, and I need to configure it to round all outputs to $3$ decimal places and be able to take command line inputs. I$\text{'}$m not sure where to go from here.

import numpy as np

def logistic$($x$,$ r$)$:

return r $*$ x $*(1-$ x$)$

def simulate$($x$0,$ r$,$ n$\_$steps, output$\_$file$)$:

population $=$ np$.$zeros$($n$\_$steps $+1)$

population$[0]=$ x$0$

for i in range$(1,$ n$\_$steps $+1)$:

population$[$i$]=$ logistic$($population$[$i $-1],$ r$)$

round$($population$[$i$],3)$

with open$($output$\_$file, $"$w$")$ as f:

for i in range$($n$\_$steps $+1)$:

f$.$write$($f$"\{$i$\}\backslash$t$\{$population$[$i$]\}$

$")$

if $\_\_$name$\_\_=="\_\_$main$\_\_"$:

x$0=2\mathrm{.}5$

r $=0\mathrm{.}1$

n$\_$steps $=200$

output$\_$file $=$ "population.txt$"$

simulate$($x$0,$ r$,$ n$\_$steps, output$\_$file$)$