from sys import argv

script_name,input_file = argv

def print_all(f):
	print f.read()

def rewind(f):
	f.seek(0)

def print_a_line(line_count,f):
	print line_count, f.readline()

current_file = open(input_file)

print "First lets print the whole file. \n"
print_all(current_file)

print "Now lets rewind "
rewind(current_file)

print "lets print three lines"
current_line=1
print_a_line(current_line,current_file)
current_line = current_line+1
print_a_line(current_line,current_file)
current_line = current_line+1
print_a_line(current_line,current_file)
 