Consideration of Python 3 environment

[lee1043]

Current version of the code works in the Python 2 environment but not considering the Python 3 environment. Most recent version of cdms has moved toward Python 3 env.

Major differences are:

1. usage of print

• Py 2: print 'abc'
• Py 3: print('abc')

We can import from __future__ import print_function at the beginning of codes which use print statement and revise print in Py 3 style, then the code will work in both Py 2 and 3 env.

2. integer divided by integer

• Py 2: int/int = int
• Py 3: int/int = float

We need to make sure the code does what we want.