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| Range Method |
Range Function
If you do need to iterate over a sequence of numbers, the built-in function range() comes in handy. It generates arithmetic progressions:
Example Usage
for i in range(5):
print(i)
Output
0
1
2
3
4
Example with optional additional arguments
The first argument, start, is the starting number of the sequence.
The second argument, stop, means to generate numbers up to, but not including this number.
The third argument, step, is the amount to increment by. In other words, it's the difference between each number in the sequence. It defaults to 1 if step is not specified.
for i in range(3, 12, 2):
print(i)
Output
3
5
7
9
11
Notes
In Python 2, there are 2 functions for going through a range of numbers: range() and xrange(). Out of these functions, xrange() is the "lazy" function, meaning it generates numbers as necessary instead of actually creating a list of numbers and iterating through them. range(), on the other hand, makes an entire list of numbers and iterates through this list. This makes it a strain on the memory in the case of really long lists.
In Python 3, the range() function mimics xrange() as the "lazy" variant, and xrange() itself has been removed.