Function Name:
range
Function Signature:
range(stop)
range(start, stop[, step])
Function Overview:
- The range() function is the constructor for the range class and return a range object
- Range in is an immutable sequence type in Python.
- Ranges represent a sequence of integers starting and ending at specified values.
- Ranges have intervals.
- The next value of a python range is defined by
nextvalue = previous value + interval value
where nextvalue < stop value
- Ranges are preferred over a list or tuple because they do not store the whole sequences.
- Regardless of the length of the sequences they represent, range objects occupy the same amount of memory as only the starting value, stopping value and the interval are specified.
- Ranges have the default start value of zero.
- The default value for the interval is one, and is represented by the step parameter.
- Ranges support operations like accessing the elements by index, slicing and the other common sequence operations as defined by collections.abc.Sequence interface.
- Since ranges represent integer sequences, the sequence represented by a range could contain negative numbers as well.
- As with any sequence in Python negative indexes represent positions from the end of the sequence.
Example:
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# Range - starting from zero and ending at 9 print("Integers zero to 9:") r1 = range(10) for elem in r1: print(elem)
print("===") # Range of even numbers less than 15 print("Even numbers less than 15:") r1 = range(2,15,2) for elem in r1: print(elem)
print("===") # Range of odd numbers less than 15 print("Odd numbers less than 15:") r1 = range(1,15,2) for elem in r1: print(elem) |
Output:
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Integers zero to 9: 0 1 2 3 4 5 6 7 8 9 === Even numbers less than 15: 2 4 6 8 10 12 14 === Odd numbers less than 15: 1 3 5 7 9 11 13 |