Document another recipe for itertools: all_equal(). Inspired by David Beazley.

1 files changed, 5 insertions, 0 deletions

diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index 9dac5e1921..a9d10736d1 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -693,6 +693,11 @@ which incur interpreter overhead.
        "Returns the nth item or a default value"
        return next(islice(iterable, n, None), default)
 
+   def all_equal(iterable):
+       "Returns True if all the elements are equal to each other"
+       g = groupby(iterable)
+       return next(g, True) and not next(g, False)
+
    def quantify(iterable, pred=bool):
        "Count how many times the predicate is true"
        return sum(map(pred, iterable))