Repeating iterator that returns the item from the parent iterator multiple times before moving to the next element.

1 files changed, 16 insertions, 0 deletions

diff --git a/itertoolset.py b/itertoolset.py
index 314ba0b..eb96e74 100644
--- a/itertoolset.py
+++ b/itertoolset.py
@@ -1,5 +1,21 @@
 from itertools import *
 import collections
+from copy import deepcopy
+
+def repeating_iterator(i, nreps):
+    '''Returns an iterator that emits each element of `i` multiple times specified by `nreps`.
+    The length of this iterator is the lenght of `i` times `nreps`.  This iterator
+    is safe even if the item consumer modifies the items.
+
+    >>> list(repeating_iterator('ABCD', 3)
+    ['A', 'A', 'A', 'B', 'B', 'B', 'C', 'C', 'C', 'D', 'D', 'D']
+    >>> list(repeating_iterator('ABCD', 1)
+    ['A', 'B', 'C', 'D']
+    '''
+    for item in i:
+        for counter in xrange(nreps):
+            yield deepcopy(item)
+
 
 def grouper(n, iterable, fillvalue=None):
     "grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx"