1.
You're writing a program called print_files.py that can take one or more 
files as command-line arguments and will do something with each file (for
example, print them).

Write the part of the program that ensures that whenever this program is
called with the wrong number of parameters, it print out the usage
of the program:

$ python print_files.py
print_files.py <file1> [file2] ...

In addition, to get started, if they do enter one or more files print
out the name of each of the files entered:

$ python print_files.py some_file another_file and_another_file
some_file
another_file
and_another_file