Improve three recipes in the itertools docs.
diff --git a/Doc/lib/libitertools.tex b/Doc/lib/libitertools.tex
index df73561..be53015 100644
--- a/Doc/lib/libitertools.tex
+++ b/Doc/lib/libitertools.tex
@@ -458,15 +458,21 @@
def all(seq, pred=bool):
"Returns True if pred(x) is True for every element in the iterable"
- return False not in imap(pred, seq)
+ for elem in ifilterfalse(pred, seq):
+ return False
+ return True
def any(seq, pred=bool):
- "Returns True if pred(x) is True at least one element in the iterable"
- return True in imap(pred, seq)
+ "Returns True if pred(x) is True for at least one element in the iterable"
+ for elem in ifilter(pred, seq):
+ return True
+ return False
def no(seq, pred=bool):
"Returns True if pred(x) is False for every element in the iterable"
- return True not in imap(pred, seq)
+ for elem in ifilter(pred, seq):
+ return False
+ return True
def quantify(seq, pred=bool):
"Count how many times the predicate is True in the sequence"
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index e4c29ad..6ce758a 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -746,15 +746,21 @@
>>> def all(seq, pred=bool):
... "Returns True if pred(x) is True for every element in the iterable"
-... return False not in imap(pred, seq)
+... for elem in ifilterfalse(pred, seq):
+... return False
+... return True
>>> def any(seq, pred=bool):
... "Returns True if pred(x) is True for at least one element in the iterable"
-... return True in imap(pred, seq)
+... for elem in ifilter(pred, seq):
+... return True
+... return False
>>> def no(seq, pred=bool):
... "Returns True if pred(x) is False for every element in the iterable"
-... return True not in imap(pred, seq)
+... for elem in ifilter(pred, seq):
+... return False
+... return True
>>> def quantify(seq, pred=bool):
... "Count how many times the predicate is True in the sequence"