[pypy-svn] r8804 - in pypy/dist: lib-python-2.3.4 pypy/lib/test2 pypy/module

adim at codespeak.net adim at codespeak.net
Wed Feb 2 14:08:26 CET 2005


Author: adim
Date: Wed Feb  2 14:08:26 2005
New Revision: 8804

Added:
   pypy/dist/lib-python-2.3.4/itertools.py
   pypy/dist/pypy/lib/test2/test_itertools.py
      - copied, changed from r8803, pypy/dist/lib-python-2.3.4/test/test_itertools.py
Modified:
   pypy/dist/pypy/module/__builtin__module.py
   pypy/dist/pypy/module/sysinterp.py
Log:
- added Python implementation of itertools
- removed an assertion in test_itertools.py for something
  not feasible in PyPy (C optmization dealing with refcount
  for izip()) and added the modified file in pypy/lib/test2
- removed itertools from the "stolen modules" list
- modified enumerate() so that it raises a TypeError instead of
  AttributeError when "next()" is not defined on the iterator
  used inside enumerate.


Added: pypy/dist/lib-python-2.3.4/itertools.py
==============================================================================
--- (empty file)
+++ pypy/dist/lib-python-2.3.4/itertools.py	Wed Feb  2 14:08:26 2005
@@ -0,0 +1,629 @@
+"""Functional tools for creating and using iterators.
+
+Infinite iterators:
+count([n]) --> n, n+1, n+2, ...
+cycle(p) --> p0, p1, ... plast, p0, p1, ...
+repeat(elem [,n]) --> elem, elem, elem, ... endlessly or up to n times
+
+Iterators terminating on the shortest input sequence:
+izip(p, q, ...) --> (p[0], q[0]), (p[1], q[1]), ... 
+ifilter(pred, seq) --> elements of seq where pred(elem) is True
+ifilterfalse(pred, seq) --> elements of seq where pred(elem) is False
+islice(seq, [start,] stop [, step]) --> elements from
+       seq[start:stop:step]
+imap(fun, p, q, ...) --> fun(p0, q0), fun(p1, q1), ...
+starmap(fun, seq) --> fun(*seq[0]), fun(*seq[1]), ...
+tee(it, n=2) --> (it1, it2 , ... itn) splits one iterator into n
+chain(p, q, ...) --> p0, p1, ... plast, q0, q1, ... 
+takewhile(pred, seq) --> seq[0], seq[1], until pred fails
+dropwhile(pred, seq) --> seq[n], seq[n+1], starting when pred fails
+groupby(iterable[, keyfunc]) --> sub-iterators grouped by value of keyfunc(v)
+"""
+
+__all__ = ['chain', 'count', 'cycle', 'dropwhile', 'groupby', 'ifilter',
+           'ifilterfalse', 'imap', 'islice', 'izip', 'repeat', 'starmap',
+           'takewhile', 'tee']
+
+
+class chain:
+    """Make an iterator that returns elements from the first iterable
+    until it is exhausted, then proceeds to the next iterable, until
+    all of the iterables are exhausted. Used for treating consecutive
+    sequences as a single sequence.
+
+    Equivalent to :
+
+    def chain(*iterables):
+        for it in iterables:
+            for element in it:
+                yield element
+    """
+    def __init__(self, *iterables):
+        self._iterables_iter = iter(map(iter, iterables))
+        # little trick for the first chain.next() call
+        self._cur_iterable_iter = iter([])
+
+    def __iter__(self):
+        return self
+    
+    def next(self):
+        try:
+            next_elt = self._cur_iterable_iter.next()
+        except StopIteration:
+            # The current list's iterator is exhausted, switch to next one
+            self._cur_iterable_iter = iter(self._iterables_iter.next())
+            try:
+                next_elt = self._cur_iterable_iter.next()
+            except AttributeError:
+                # CPython raises a TypeError when next() is not defined
+                raise TypeError('%s has no next() method' % \
+                                (self._cur_iterable_iter))
+        except AttributeError:
+            # CPython raises a TypeError when next() is not defined
+            raise TypeError('%s has no next() method' % \
+                            (self._cur_iterable_iter))
+            
+        return next_elt
+            
+
+class count:
+    """Make an iterator that returns consecutive integers starting
+    with n.  If not specified n defaults to zero. Does not currently
+    support python long integers. Often used as an argument to imap()
+    to generate consecutive data points.  Also, used with izip() to
+    add sequence numbers.
+
+    Equivalent to :
+
+    def count(n=0):
+        if not isinstance(n, int):
+            raise TypeError("%s is not a regular integer" % n)
+        while True:
+            yield n
+            n += 1
+    """
+    def __init__(self, n=0):
+        if not isinstance(n, int):
+            raise TypeError('%s is not a regular integer' % n)
+        self.times = n-1
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        self.times += 1
+        return self.times
+
+    def __repr__(self):
+        return 'count(%d)' % (self.times + 1)
+
+
+            
+class cycle:
+    """Make an iterator returning elements from the iterable and
+    saving a copy of each. When the iterable is exhausted, return
+    elements from the saved copy. Repeats indefinitely.
+
+    Equivalent to :
+
+    def cycle(iterable):
+        saved = []
+        for element in iterable:
+            yield element
+            saved.append(element)
+        while saved:
+            for element in saved:
+                yield element    
+    """
+    def __init__(self, iterable):
+        self._cur_iter = iter(iterable)
+        self._saved = []
+        self._must_save = True
+        
+    def __iter__(self):
+        return self
+
+    def next(self):
+        # XXX Could probably be improved
+        try:
+            next_elt = self._cur_iter.next()
+            if self._must_save:
+                self._saved.append(next_elt)
+        except StopIteration:
+            self._cur_iter = iter(self._saved)
+            next_elt = self._cur_iter.next()
+            self._must_save = False
+        except AttributeError:
+            # CPython raises a TypeError when next() is not defined
+            raise TypeError('%s has no next() method' % \
+                            (self._cur_iter))
+        return next_elt
+            
+        
+class dropwhile:
+    """Make an iterator that drops elements from the iterable as long
+    as the predicate is true; afterwards, returns every
+    element. Note, the iterator does not produce any output until the
+    predicate is true, so it may have a lengthy start-up time.
+
+    Equivalent to :
+
+    def dropwhile(predicate, iterable):
+        iterable = iter(iterable)
+        for x in iterable:
+            if not predicate(x):
+                yield x
+                break
+        for x in iterable:
+            yield x
+    """
+    def __init__(self, predicate, iterable):
+        self._predicate = predicate
+        self._iter = iter(iterable)
+        self._dropped = False
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        try:
+            value = self._iter.next()
+        except AttributeError:
+            # CPython raises a TypeError when next() is not defined
+            raise TypeError('%s has no next() method' % \
+                            (self._iter))
+        if self._dropped:
+            return value
+        while self._predicate(value):
+            value = self._iter.next()
+        self._dropped = True
+        return value
+
+class groupby:
+    """Make an iterator that returns consecutive keys and groups from the
+    iterable. The key is a function computing a key value for each
+    element. If not specified or is None, key defaults to an identity
+    function and returns the element unchanged. Generally, the
+    iterable needs to already be sorted on the same key function.
+
+    The returned group is itself an iterator that shares the
+    underlying iterable with groupby(). Because the source is shared,
+    when the groupby object is advanced, the previous group is no
+    longer visible. So, if that data is needed later, it should be
+    stored as a list:
+
+       groups = []
+       uniquekeys = []
+       for k, g in groupby(data, keyfunc):
+           groups.append(list(g))      # Store group iterator as a list
+           uniquekeys.append(k)
+    """    
+    def __init__(self, iterable, key=None):
+        if key is None:
+            key = lambda x: x
+        self.keyfunc = key
+        self.it = iter(iterable)
+        self.tgtkey = self.currkey = self.currvalue = xrange(0)
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        while self.currkey == self.tgtkey:
+            try:
+                self.currvalue = self.it.next() # Exit on StopIteration
+            except AttributeError:
+                # CPython raises a TypeError when next() is not defined
+                raise TypeError('%s has no next() method' % \
+                                (self.it))            
+            self.currkey = self.keyfunc(self.currvalue)
+        self.tgtkey = self.currkey
+        return (self.currkey, self._grouper(self.tgtkey))
+
+    def _grouper(self, tgtkey):
+        while self.currkey == tgtkey:
+            yield self.currvalue
+            self.currvalue = self.it.next() # Exit on StopIteration
+            self.currkey = self.keyfunc(self.currvalue)
+
+
+
+class _ifilter_base:
+    """base class for ifilter and ifilterflase"""
+    def __init__(self, predicate, iterable):
+        # Make sure iterable *IS* iterable
+        self._iter = iter(iterable)
+        if predicate is None:
+            self._predicate = bool
+        else:
+            self._predicate = predicate
+
+    def __iter__(self):
+        return self
+    
+class ifilter(_ifilter_base):
+    """Make an iterator that filters elements from iterable returning
+    only those for which the predicate is True.  If predicate is
+    None, return the items that are true.
+
+    Equivalent to :
+
+    def ifilter:
+        if predicate is None:
+            predicate = bool
+        for x in iterable:
+            if predicate(x):
+                yield x
+    """
+    def next(self):
+        try:
+            next_elt = self._iter.next()
+        except AttributeError:
+            # CPython raises a TypeError when next() is not defined
+            raise TypeError('%s has no next() method' % \
+                            (self._iter))
+        while True:
+            if self._predicate(next_elt):
+                return next_elt
+            next_elt = self._iter.next()
+
+class ifilterfalse(_ifilter_base):
+    """Make an iterator that filters elements from iterable returning
+    only those for which the predicate is False.  If predicate is
+    None, return the items that are false.
+
+    Equivalent to :
+    
+    def ifilterfalse(predicate, iterable):
+        if predicate is None:
+            predicate = bool
+        for x in iterable:
+            if not predicate(x):
+                yield x
+    """
+    def next(self):
+        try:
+            next_elt = self._iter.next()
+        except AttributeError:
+            # CPython raises a TypeError when next() is not defined
+            raise TypeError('%s has no next() method' % \
+                            (self._iter))
+        while True:
+            if not self._predicate(next_elt):
+                return next_elt
+            next_elt = self._iter.next()
+             
+
+
+
+class imap:
+    """Make an iterator that computes the function using arguments
+    from each of the iterables. If function is set to None, then
+    imap() returns the arguments as a tuple. Like map() but stops
+    when the shortest iterable is exhausted instead of filling in
+    None for shorter iterables. The reason for the difference is that
+    infinite iterator arguments are typically an error for map()
+    (because the output is fully evaluated) but represent a common
+    and useful way of supplying arguments to imap().
+
+    Equivalent to :
+
+    def imap(function, *iterables):
+        iterables = map(iter, iterables)
+        while True:
+            args = [i.next() for i in iterables]
+            if function is None:
+                yield tuple(args)
+            else:
+                yield function(*args)
+    
+    """
+    def __init__(self, function, iterable, *other_iterables):
+        self._func = function
+        self._iters = map(iter, (iterable, ) + other_iterables)
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        try:
+            args = [it.next() for it in self._iters]
+        except AttributeError:
+            # CPython raises a TypeError when next() is not defined
+            raise TypeError('%s has no next() method' % \
+                            (it))
+        if self._func is None:
+            return tuple(args)
+        else:
+            return self._func(*args)
+
+
+
+class islice:
+    """Make an iterator that returns selected elements from the
+    iterable.  If start is non-zero, then elements from the iterable
+    are skipped until start is reached. Afterward, elements are
+    returned consecutively unless step is set higher than one which
+    results in items being skipped. If stop is None, then iteration
+    continues until the iterator is exhausted, if at all; otherwise,
+    it stops at the specified position. Unlike regular slicing,
+    islice() does not support negative values for start, stop, or
+    step. Can be used to extract related fields from data where the
+    internal structure has been flattened (for example, a multi-line
+    report may list a name field on every third line).
+
+    Equivalent to :
+
+    def islice(iterable, *args):
+        s = slice(*args)
+        next, stop, step = s.start or 0, s.stop, s.step or 1
+        for cnt, element in enumerate(iterable):
+            if cnt < next:
+                continue
+            if stop is not None and cnt >= stop:
+                break
+            yield element
+            next += step
+    """
+    def __init__(self, iterable, arg, *other_args):
+        if len(other_args) > 2 :
+            raise TypeError("islice() takes at most 4 arguments, got %s" %
+                            (2 + len(other_args)))
+        self._enum = enumerate(iterable)
+        start, stop, step = 0, -1, 1
+        # We must do the same checks that in the CPython implementation
+        # Only one arg passed means it's the "stop" one
+        if not other_args:
+            stop = arg
+        else:
+            start = arg
+            try:
+                stop, step = other_args
+            except ValueError: # <=> No step specified
+                stop = other_args[0]
+            if not isinstance(start, int):
+                raise ValueError("Start argument must be an integer")
+        if stop is not None and not isinstance(stop, int):
+            raise ValueError("Stop argument must be an integer or None")
+        if start < 0 or (stop is not None and stop < -1):
+            raise ValueError("Indices for islice() must be non-negative integers.")
+        if step < 1:
+            raise ValueError("Step must be one or larger for islice()")
+        s = slice(start, stop, step)
+        self._next, self._stop, self._step = start, stop, step
+        # self._next, self._stop, self._step = s.start or 0, s.stop, s.step or 1
+        
+        
+    def __iter__(self):
+        return self
+
+    def next(self):
+        while True:
+            index, element = self._enum.next()
+            if self._stop is not None and index >= self._stop:
+                raise StopIteration()
+            if index < self._next:
+                continue
+            self._next += self._step
+            return element
+        
+        
+
+class izip:
+    """Make an iterator that aggregates elements from each of the
+    iterables.  Like zip() except that it returns an iterator instead
+    of a list. Used for lock-step iteration over several iterables at
+    a time.
+
+    Equivalent to :
+
+    def izip(*iterables):
+        iterables = map(iter, iterables)
+        while iterables:
+            result = [i.next() for i in iterables]
+            yield tuple(result)
+    """
+    def __init__(self, *iterables):
+        self._iterators = map(iter, iterables)
+        self._result = [None] * len(self._iterators)
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        if not self._iterators:
+            raise StopIteration()
+        try:
+            return tuple([i.next() for i in self._iterators])
+        except AttributeError:
+            # CPython raises a TypeError when next() is not defined
+            raise TypeError('%s has no next() method' % (i))
+    
+
+class repeat:
+    """Make an iterator that returns object over and over again.
+    Runs indefinitely unless the times argument is specified.  Used
+    as argument to imap() for invariant parameters to the called
+    function. Also used with izip() to create an invariant part of a
+    tuple record.
+
+    Equivalent to :
+
+    def repeat(object, times=None):
+        if times is None:
+            while True:
+                yield object
+        else:
+            for i in xrange(times):
+                yield object
+    """
+    def __init__(self, obj, times=None):
+        self._obj = obj
+        if times is not None:
+            xrange(times) # Raise a TypeError
+            if times < 0:
+                times = 0
+        self._times = times
+        
+    def __iter__(self):
+        return self
+
+    def next(self):
+        # next() *need* to decrement self._times when consumed
+        if self._times is not None:
+            if self._times <= 0: 
+                raise StopIteration()
+            self._times -= 1
+        return self._obj
+
+    def __repr__(self):
+        if self._times is not None:
+            return 'repeat(%r, %r)' % (self._obj, self._times)
+        else:
+            return 'repeat(%r)' % (self._obj,)
+
+    def __len__(self):
+        if self._times == -1 or self._times is None:
+            raise TypeError("len() of uniszed object")
+        return self._times
+    
+
+class starmap:
+    """Make an iterator that computes the function using arguments
+    tuples obtained from the iterable. Used instead of imap() when
+    argument parameters are already grouped in tuples from a single
+    iterable (the data has been ``pre-zipped''). The difference
+    between imap() and starmap() parallels the distinction between
+    function(a,b) and function(*c).
+
+    Equivalent to :
+
+    def starmap(function, iterable):
+        iterable = iter(iterable)
+        while True:
+            yield function(*iterable.next())    
+    """
+    def __init__(self, function, iterable):
+        self._func = function
+        self._iter = iter(iterable)
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        # CPython raises a TypeError when the iterator doesn't return a tuple
+        try:
+            t = self._iter.next()
+        except AttributeError:
+            # CPython raises a TypeError when next() is not defined
+            raise TypeError('%s has no next() method' % self._iter)
+        if not isinstance(t, tuple):
+            raise TypeError("iterator must return a tuple")
+        return self._func(*t)
+
+
+
+class takewhile:
+    """Make an iterator that returns elements from the iterable as
+    long as the predicate is true.
+
+    Equivalent to :
+    
+    def takewhile(predicate, iterable):
+        for x in iterable:
+            if predicate(x):
+                yield x
+            else:
+                break
+    """
+    def __init__(self, predicate, iterable):
+        self._predicate = predicate
+        self._iter = iter(iterable)
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        try:
+            value = self._iter.next()
+        except AttributeError:
+            # CPython raises a TypeError when next() is not defined
+            raise TypeError('%s has no next() method' % \
+                            (self._iter))
+        if not self._predicate(value):
+            raise StopIteration()
+        return value
+
+    
+class TeeData(object):
+    """Holds cached values for TeeObjects"""
+    def __init__(self, iterator):
+        self.data = []
+        self._iter = iterator
+
+    def __getitem__(self, i):
+        # iterates until 'i' if not done yet
+        while i>= len(self.data):
+            try:
+                self.data.append( self._iter.next() )
+            except AttributeError:
+                # CPython raises a TypeError when next() is not defined
+                raise TypeError('%s has no next() method' % self._iter)
+        return self.data[i]
+
+
+class TeeObject(object):
+    """Iterables / Iterators as returned by the tee() function"""
+    def __init__(self, iterable=None, tee_data=None):
+        if tee_data:
+            self.tee_data = tee_data
+            self.pos = 0
+        # <=> Copy constructor
+        elif isinstance(iterable, TeeObject):
+            self.tee_data = iterable.tee_data
+            self.pos = iterable.pos
+        else:
+            self.tee_data = TeeData(iter(iterable))
+            self.pos = 0
+            
+    def next(self):
+        data = self.tee_data[self.pos]
+        self.pos += 1
+        return data
+    
+    def __iter__(self):
+        return self
+
+    
+def tee(iterable, n=2):
+    """Return n independent iterators from a single iterable.
+    Note : once tee() has made a split, the original iterable
+    should not be used anywhere else; otherwise, the iterable could get
+    advanced without the tee objects being informed.
+    
+    Note : this member of the toolkit may require significant auxiliary
+    storage (depending on how much temporary data needs to be stored).
+    In general, if one iterator is going to use most or all of the
+    data before the other iterator, it is faster to use list() instead
+    of tee()
+    
+    Equivalent to :
+    
+    def tee(iterable, n=2):
+        def gen(next, data={}, cnt=[0]):
+            for i in count():
+                if i == cnt[0]:
+                    item = data[i] = next()
+                    cnt[0] += 1
+                else:
+                    item = data.pop(i)
+                yield item
+        it = iter(iterable)
+        return tuple([gen(it.next) for i in range(n)])
+    """
+    if isinstance(iterable, TeeObject):
+        # a,b = tee(range(10)) ; c,d = tee(a) ; self.assert_(a is c)
+        return tuple([iterable] +
+        [TeeObject(tee_data=iterable.tee_data) for i in xrange(n-1)])
+    tee_data = TeeData(iter(iterable))
+    return tuple([TeeObject(tee_data=tee_data) for i in xrange(n)])

Copied: pypy/dist/pypy/lib/test2/test_itertools.py (from r8803, pypy/dist/lib-python-2.3.4/test/test_itertools.py)
==============================================================================
--- pypy/dist/lib-python-2.3.4/test/test_itertools.py	(original)
+++ pypy/dist/pypy/lib/test2/test_itertools.py	Wed Feb  2 14:08:26 2005
@@ -95,8 +95,9 @@
                          zip('abc', 'def'))
         self.assertEqual([pair for pair in izip('abc', 'def')],
                          zip('abc', 'def'))
-        ids = map(id, izip('abc', 'def'))
-        self.assertEqual(min(ids), max(ids))
+
+        # ids = map(id, izip('abc', 'def'))
+        # self.assertEqual(min(ids), max(ids)) ## NOT FEASIBLE IN PYPY
         ids = map(id, list(izip('abc', 'def')))
         self.assertEqual(len(dict.fromkeys(ids)), len(ids))
 

Modified: pypy/dist/pypy/module/__builtin__module.py
==============================================================================
--- pypy/dist/pypy/module/__builtin__module.py	(original)
+++ pypy/dist/pypy/module/__builtin__module.py	Wed Feb  2 14:08:26 2005
@@ -466,7 +466,11 @@
         return self
 
     def next(self):
-        value = self.iter.next()
+        try:
+            value = self.iter.next()
+        except AttributeError:
+            # CPython raises a TypeError when next() is not defined
+            raise TypeError('%s has no next() method' % self.iter)
         index = self.index
         self.index += 1
         return index, value

Modified: pypy/dist/pypy/module/sysinterp.py
==============================================================================
--- pypy/dist/pypy/module/sysinterp.py	(original)
+++ pypy/dist/pypy/module/sysinterp.py	Wed Feb  2 14:08:26 2005
@@ -36,7 +36,7 @@
 # The following built-in modules are not written in PyPy, so we
 # steal them from Python.
 for fn in ['posix', 'nt', 'os2', 'mac', 'ce', 'riscos',
-           'itertools', 'math', '_codecs', 'array',
+           'math', '_codecs', 'array',
            '_random', '_sre', 'time', '_socket', 'errno',
            'marshal', 'binascii', 'parser']:
     if fn not in builtin_modules:



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