The step_info command returns a Python dictionary object with the properties of the step response. The for loop in the example iterates over the keys of the dictionary and prints the name of the key and its value.

For your example, it turns out there is a small twist: the undershoot is zero and so the format string above will generate an error due to the way that 3.4 is interpreted (this format string only works for floats). But you can retrieve the values just by looking at the key-value pairs in S. Using ipython, I get:

{'RiseTime': 0.9768542818762616,
 'SettlingTime': 7.814834255010094,
 'SettlingMin': 0.9069710996980537,
 'SettlingMax': 1.305008244865823,
 'Overshoot': 30.50082448658229,
 'Undershoot': 0,
 'Peak': 1.305008244865823,
 'PeakTime': 2.37236039884235,
 'SteadyStateValue': 1.0}