24/nov/2017 Range/xrange

RANGE_XRANGE.PY

Python2 --Range
1.It produces a list for itertions.
For x in range(3):
         print x
O/p:
0
1
2

y = range(5)
type(y)
<type 'list'>
x = [0,1,2,3,4]
===============================================
Python2 --Xrange
for x in xrange(5):
 print x

Output:
0
1
2
3
4
//as if now working same as for range

y = xrange(3)
print y
>>output:
xrange(3)
->xrange function returns you a sequence object which have 
to be iterated if it is required to be used.
>>> it = iter(y)
>>> it.next
<method-wrapper 'next' of rangeiterator object at 0x0000000001D95F50>
>>> it.next()
0
>>it.next()
1
>>> it.next()
2
>>> it.next()

Traceback (most recent call last):
  File "<pyshell#12>", line 1, in <module>
    it.next()
StopIteration  ### when it reaches beyond the last iteration
**xrange doesn't create the list at once , it makes one by one.
**mainly benificial when lack of memory , the range creates a list all
together(for e.g for iterations over million of no.s e.g cell phone)
whereas xranges generators iterations when asked for.
==============================================
Python3 range
IN Python 3 
type(range)
<type range>
==============
Python3 xrange
IN Python 3 
type(range)
<type range>