Pandas for Everyone: Python Data Analysis, First Edition

P. Ranges and Generators

The Python range function allows the user to create a sequence of values by providing a starting value, an ending value, and if needed, a step value. It is very similar to the slicing syntax in Appendix L. By default, if we give range a single number, this function will create a sequence of values starting from 0.

# create a range of 5 r = range(5)

However, the range function doesn’t just return a list of numbers. In Python 3, it actually returns a generator. (In Python 2, this is the behavior of the xrange function.)

print(r)

range(0, 5)

print(type(r))

<class 'range'>

If we wanted an actual list of the range, we can convert the generator to a list.

lr = list(range(5)) print(lr)

[0, 1, 2, 3, 4]

Before you decide to convert ...