Similarities and differences between xrange and range in Python

Range
Function Description: Range ([Start,] stop[, step]), generating a sequence (list)based on the range specified by start and stop and step set by step.

>>> Range (51, 2, 3, 4>>> range (1,5) [1, 2, 3, 4>>> range ( 0,6,22, 4]

Xrange
Function Description: The usage is exactly the same as range, the difference is not an array, but a generator .
xrange Example:

>>> xrange (5) xrange (5)>>> list (xrange (51, 2, 3, 4) >> > xrange (1,5) xrange (1, 5)>>> list (xrange (1,5)) [1, 2, 3, 4]>> > xrange (0,6,26, 2)>>> list (xrange (0,6,22, 4)

As can be known from the above example: to generate a large number sequence, using xrange will be much better than range performance, because there is no need to open up a large amount of memory space, both of which are basically used in the loop:

 for  in range (0, +):     print for in xrange (0, +):      Print

The results of both outputs are the same, in fact there are many differences, and range generates a list object directly:

A = Range (0,100print Print Print

Output Result:

' List '>1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55 , 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 94, 98,1, $,------

Xrange does not generate a list directly, but instead returns one of the values for each call:

A = xrange (0,100print Print Print

Output Result:

' xrange '>xrange (1

So xrange do loop performance better than range, especially when returning very large, try to use Xrange bar, unless you are going to return a list.

Similarities and differences between xrange and range in Python