Use the format function of python,
The new format is a format string python2.6 method, a method with respect to the old version of the format%, it has many advantages.
1 does not need to care about the data type of problem, a method in% in% s only replace string type
2. A single parameter can output a plurality of times, the order may not be the same parameter
3. Fill mode is very flexible, very strong alignment
4. official recommended way, way% will be eliminated in a later version
