Holds onto stdin for specified number of seconds (or default 2) and then pipes to stdout.

sleepPipe.py

#!/usr/bin/env python3
# takes stdin, sleeps, outputs to stdout
import sys
import time

def main():
    if len(sys.argv) > 1:
        sleep_time = int(sys.argv[1])
    else:
        sleep_time = 2
    time.sleep(sleep_time)
    print(sys.stdin.read(), end="")

if __name__ == '__main__':
    main()