Python, cf-python and cf-plot version 3 changes

Python 3 changes

The headline change that everyone will see is with the print function now requiring brackets

print 'output is ', output <--- Python 2

print('output is ', output) <--- Python 3

Integer arithmetic has changed and now requires // rather than /:

3/2 = 1 <--- Python 2

3/2 = 1.5 <--- Python 3

3//2 = 1 <--- Python 3

Use range rather than xrange for iterable loops:

for i in xrange(10): <--- Python 2

for i in range(10): <--- Python 3

Unicode has changed.

See The key differences between Python 2.7.x and Python 3.x with examples for more details.

cf-python 3 changes

To see what is in a cf field in cf-python 3 use g.construct instead of g.item.

For example, to see what levels are available in the temperature data use:

g.construct('longitude').array - uses the standard_name attribute if it exists

g.construct('long_name=longitude').array - uses the long_name attribute(in this case the long_name is also longitude)

g.construct('X').array - uses the field X axis

For more details see differences between cf-python version 2 and version 3

Mac OSX is now supported.

cf-plot 3 changes

cf-plot 3 now uses matplotlib 3 which might cause some subtle plot differences from cf-plot 2. The colorbar is now a routine that can be called independently of a colour plot and the plot relationship to the colour bar may be subtly different because of this.

Mac OSX is now supported.

Regridding unchanged

The regridding interface and backend use of esmpy is unchanged.