Update this tutorial to Python 3

[Pharaoh00]

Hey, nice github tutorial for python... But all your code is on Python 2!
Can i start update to python 3? And make some changes, here is one example:

# from sys module import a member called 'argv'
from sys import argv
#unpack
script, filename = argv
fp = open(filename, "w")
print "Writing to file %r " % fp
fp.write("Hello World")
fp.close()

This example is from python_write.py, but here is the problem, when you are working with files if you open you need to close it.
The way to do it more "easily" is yo use context manager with statement.

So:

# from sys module import a member called 'argv'
from sys import argv
#unpack
script, filename = argv
with open(filename, "w") as f:
    print("Writing to file".format(f)) # As python 3+
    f.write("Hello World")

More clean, and modern python.