Improve docs:
* Simplify the pure python examples
* Add a quantify() example
diff --git a/Doc/lib/libitertools.tex b/Doc/lib/libitertools.tex
index d17fc6f..b708050 100644
--- a/Doc/lib/libitertools.tex
+++ b/Doc/lib/libitertools.tex
@@ -78,7 +78,7 @@
Make an iterator that returns consecutive integers starting with \var{n}.
Does not currently support python long integers. Often used as an
argument to \function{imap()} to generate consecutive data points.
- Also, used in \function{izip()} to add sequence numbers. Equivalent to:
+ Also, used with \function{izip()} to add sequence numbers. Equivalent to:
\begin{verbatim}
def count(n=0):
@@ -103,9 +103,7 @@
for element in iterable:
yield element
saved.append(element)
- if len(saved) == 0:
- return
- while True:
+ while saved:
for element in saved:
yield element
\end{verbatim}
@@ -124,13 +122,12 @@
\begin{verbatim}
def dropwhile(predicate, iterable):
iterable = iter(iterable)
- while True:
- x = iterable.next()
- if predicate(x): continue # drop when predicate is true
+ for x in iterable:
+ if not predicate(x):
+ yield x
+ break
+ for x in iterable:
yield x
- break
- while True:
- yield iterable.next()
\end{verbatim}
\end{funcdesc}
@@ -209,9 +206,7 @@
\begin{verbatim}
def islice(iterable, *args):
s = slice(*args)
- next = s.start or 0
- stop = s.stop
- step = s.step or 1
+ next, stop, step = s.start or 0, s.stop, s.step or 1
for cnt, element in enumerate(iterable):
if cnt < next:
continue
@@ -278,9 +273,7 @@
\begin{verbatim}
def takewhile(predicate, iterable):
- iterable = iter(iterable)
- while True:
- x = iterable.next()
+ for x in iterable:
if predicate(x):
yield x
else:
@@ -358,6 +351,10 @@
... "Returns True if pred(x) is False for every element in the iterable"
... return True not in imap(pred, seq)
+>>> def quantify(pred, seq):
+... "Count how many times the predicate is True in the sequence"
+... return sum(imap(pred, seq))
+
>>> def padnone(seq):
... "Returns the sequence elements and then returns None indefinitely"
... return chain(seq, repeat(None))