import time

def countdown$\_$timer$($duration$)$:

# Get the current time

start$\_$time $=$ time.time$()$

# Calculate the end time

end$\_$time $=$ start$\_$time $+$ duration

# Loop until the current time reaches the end time

while time.time$()<$ end$\_$time:

# Calculate remaining time

remaining$\_$time $=$ int$($end$\_$time $-$ time.time$())$

# Display the remaining time

print$($f$"$Time left: $\{$remaining$\_$time$\}$ seconds", end$="\backslash$r$")$

# Sleep for a short duration to reduce CPU usage

time.sleep$(1)$

# Countdown is complete

print$("$

Countdown complete!"$)$

# Example usage

countdown$\_$timer$(10)$

can you show me how to do this without the sleep function?

also what is example usage $?$ can it be written without that?