kopia lustrzana https://github.com/micropython/micropython-lib
updates:4 additions: 13 tests
updated: accumulate, chain, islice, tee; added: chain.from_iterable, combinations, combinations_with_replacement,compress, dropwhile, filterfalse, groupby, pairwise, permutations, product,takewhile, zip_longest; also added tests for all functionspull/581/head
rkompass
rodzic
0051a5ef50
commit
8698e33a77
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@ -1,74 +1,317 @@
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# Python itertools adapted for Micropython by rkompass (2022)
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# Largely, but not exclusively based on code from the offical Python documentation
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# (https://docs.python.org/3/library/itertools.html)
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# Copyright 2001-2019 Python Software Foundation; All Rights Reserved
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# consumes about 5kB if imported
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# accumulate([1,2,3,4,5]) --> 1 3 6 10 15
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# accumulate([1,2,3,4,5], initial=100) --> 100 101 103 106 110 115
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# accumulate([1,2,3,4,5], lambda x, y: x * y) --> 1 2 6 24 120
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def accumulate(iterable, func=lambda x, y: x + y, initial=None):
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it = iter(iterable)
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total = initial
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if initial is None:
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try:
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total = next(it)
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except StopIteration:
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return
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yield total
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for element in it:
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total = func(total, element)
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yield total
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# chain('abcd',[],range(5))) --> 'a' 'b' 'c' 'd' 0 1 2 3 4
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class chain:
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def __init__(self, *iterables):
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self.iterables = list(iterables)
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self.it = iter([])
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def __iter__(self):
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return self
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def __next__(self):
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while True:
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try:
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return next(self.it)
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except StopIteration:
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try:
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self.it = iter(self.iterables.pop(0))
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continue
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except IndexError:
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raise StopIteration
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# chain.from_iterable(['ABC', 'DEF']) --> 'A' 'B' 'C' 'D' 'E' 'F'
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@staticmethod
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def from_iterable(iterables):
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for it in iterables:
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yield from it
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# combinations('ABCD', 2) --> ('A','B') ('A','C') ('A','D') ('B','C') ('B','D') ('C','D')
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def combinations(iterable, r):
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pool = tuple(iterable)
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n = len(pool)
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if r > n:
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return
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indices = list(range(r))
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yield tuple(pool[i] for i in indices)
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while True:
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index = 0
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for i in reversed(range(r)):
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if indices[i] != i + n - r:
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index = i
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break
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else:
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return
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indices[index] += 1
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for j in range(index + 1, r):
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indices[j] = indices[j - 1] + 1
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yield tuple(pool[i] for i in indices)
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# combinations_with_replacement('ABC', 2) --> ('A','A') ('A','B') ('A','C') ('B','B') ('B','C') ('C','C')
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def combinations_with_replacement(iterable, r):
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pool = tuple(iterable)
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n = len(pool)
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if not n and r:
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return
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indices = [0] * r
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yield tuple(pool[i] for i in indices)
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while True:
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index = 0
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for i in reversed(range(r)):
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if indices[i] != n - 1:
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index = i
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break
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else:
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return
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indices[index:] = [indices[index] + 1] * (r - index)
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yield tuple(pool[i] for i in indices)
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# compress('ABCDEF', [1,0,1,0,1,1]) --> A C E F
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def compress(data, selectors):
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return (d for d, s in zip(data, selectors) if s)
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# count(4, 3) --> 4 7 10 13 16 19 ....
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def count(start=0, step=1):
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while True:
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yield start
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start += step
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def cycle(p):
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# cycle('abc') --> a b c a b c a b c a ....
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def cycle(iterable):
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try:
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len(p)
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except TypeError:
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# len() is not defined for this type. Assume it is
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# a finite iterable so we must cache the elements.
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len(iterable)
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except TypeError: # len() not defined: Assume p is a finite iterable: We cache the elements.
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cache = []
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for i in p:
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for i in iterable:
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yield i
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cache.append(i)
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p = cache
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while p:
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yield from p
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iterable = cache
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while iterable:
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yield from iterable
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# # dropwhile(lambda x: x<5, [1,4,6,4,1]) --> 6 4 1
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def dropwhile(predicate, iterable):
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it = iter(iterable)
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for x in it:
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if not predicate(x):
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yield x
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break
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for x in it:
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yield x
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def repeat(el, n=None):
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if n is None:
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while True:
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yield el
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else:
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for i in range(n):
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yield el
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def chain(*p):
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for i in p:
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yield from i
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def islice(p, start, stop=(), step=1):
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if stop == ():
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stop = start
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start = 0
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# TODO: optimizing or breaking semantics?
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if start >= stop:
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return
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it = iter(p)
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for i in range(start):
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next(it)
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# filterfalse(lambda x: x%2, range(10)) --> 0 2 4 6 8
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def filterfalse(predicate, iterable):
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if predicate is None:
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predicate = bool
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for x in iterable:
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if not predicate(x):
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yield x
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# groupby('aaaabbbccdaa'))) --> ('a', gen1) ('b', gen2) ('c', gen3) ('d', gen4) ('a', gen5)
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# where gen1 --> a a a a, gen2 --> b b b, gen3 --> c c, gen4 --> d, gen5 --> a a
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def groupby(iterable, key=None):
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it = iter(iterable)
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keyf = key if key is not None else lambda x: x
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def ggen(ktgt):
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nonlocal cur, kcur
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while kcur == ktgt:
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yield cur
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try:
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cur = next(it); kcur = keyf(cur)
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except StopIteration:
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break
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kcur = kold = object() # need an object that never can be a returned from key function
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while True:
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yield next(it)
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for i in range(step - 1):
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while kcur == kold: # not all iterables with the same (old) key were used up by ggen, so use them up here
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try:
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cur = next(it); kcur = keyf(cur)
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except StopIteration:
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return
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kold = kcur
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yield (kcur, ggen(kcur))
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# islice('abcdefghij', 2, None, 3)) --> c f i
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# islice(range(10), 2, 6, 2)) --> 2 4
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def islice(iterable, *sargs):
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if len(sargs) < 1 or len(sargs) > 3:
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raise TypeError('islice expected at least 2, at most 4 arguments, got {:d}'.format(len(sargs)+1))
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step = 1 if len(sargs) < 3 else sargs[2]
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step = 1 if step is None else step
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if step <= 0:
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raise ValueError('step for islice() must be a positive integer or None')
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start = 0 if len(sargs) < 2 else sargs[0]
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stop = sargs[0] if len(sargs) == 1 else sargs[1]
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it = iter(iterable)
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try:
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for i in range(start):
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next(it)
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start += step
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if start >= stop:
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while True:
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if stop is not None and start >= stop:
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return
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yield next(it)
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for i in range(step - 1):
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next(it)
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start += step
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except StopIteration:
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return
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# pairwise(range(5)) --> (0,1) (1,2) (2,3) (3,4)
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# pairwise('abcdefg') --> ('a','b') ('b','c') ('c','d') ('d','e') ('e','f') ('f','g')
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def pairwise(iterable):
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it = iter(iterable)
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try:
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l = next(it)
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while True:
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c = next(it)
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yield l, c
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l = c
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except StopIteration:
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return
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# permutations('ABCD', 2) --> AB AC AD BA BC BD CA CB CD DA DB DC
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# permutations(range(3)) --> 012 021 102 120 201 210
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def permutations(iterable, r=None):
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pool = tuple(iterable)
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n = len(pool)
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r = n if r is None else r
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if r > n:
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return
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indices = list(range(n))
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cycles = list(range(n, n - r, -1))
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yield tuple(pool[i] for i in indices[:r])
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while n:
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for i in reversed(range(r)):
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cycles[i] -= 1
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if cycles[i] == 0:
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indices[i:] = indices[i + 1 :] + indices[i : i + 1]
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cycles[i] = n - i
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else:
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j = cycles[i]
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indices[i], indices[-j] = indices[-j], indices[i]
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yield tuple(pool[i] for i in indices[:r])
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break
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else:
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return
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# product('ABCD', 'xy') --> ('A','x') ('A','y') ('B','x') ('B','y') ('C','x') ('C','y') ('D','x') ('D','y')
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# product(range(2), repeat=3) --> 000 001 010 011 100 101 110 111 # but in tuples, of course
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def product(*args, repeat=1):
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pools = [tuple(pool) for pool in args] * repeat
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result = [[]]
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for pool in pools:
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result = [x + [y] for x in result for y in pool]
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for prod in result:
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yield tuple(prod)
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def tee(iterable, n=2):
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return [iter(iterable)] * n
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# repeat(10, 3) --> 10 10 10
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def repeat(obj, times=None):
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if times is None:
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while True:
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yield obj
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else:
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for _ in range(times):
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yield obj
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# starmap(pow, [(2,5), (3,2), (10,3)]) --> 32 9 1000
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def starmap(function, iterable):
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for args in iterable:
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yield function(*args)
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# takewhile(lambda x: x<5, [1,4,6,4,1]) --> 1 4
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def takewhile(predicate, iterable):
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for x in iterable:
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if predicate(x):
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yield x
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else:
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break
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def accumulate(iterable, func=lambda x, y: x + y):
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# tee(range(2,10), 3) --> (it1, it2, it3) all parallel generators, but dependent on original generator (e.g. range(2,10))
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# --> (min(it1), max(it2), sum(it3)) --> (2, 9, 44)
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def tee(iterable, n=2):
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if iter(iterable) is not iter(iterable): # save buffer for special cases that iterable is range, tuple, list ...
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return [iter(iterable) for _ in range(n)] # that have independent iterators
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it = iter(iterable)
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try:
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acc = next(it)
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except StopIteration:
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if n < 1:
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return ()
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elif n == 1:
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return (it,)
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buf = [] # Buffer, contains stored values from itr
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ibuf = [0]*n # Indices of the individual generators, could be array('H', [0]*n)
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def gen(k): # but we have no 0 in ibuf in MP
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nonlocal buf, ibuf # These are bound to the generators as closures
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while True:
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if ibuf[k] < len(buf): # We get an object stored in the buffer.
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r = buf[ibuf[k]]
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ibuf[k] += 1
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if ibuf[k] == 1: # If we got the first object in the buffer,
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if 0 not in ibuf: # then check if other generators do not wait anymore on it
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buf.pop(0) # so it may be popped left. Afterwards decrease all indices by 1.
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for i in range(n):
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ibuf[i] -= 1
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elif ibuf[k] == len(buf):
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try:
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r = next(it)
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buf.append(r)
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ibuf[k] += 1
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except StopIteration:
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return
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yield r # The returned generators are not thread-safe. For that the access to the
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return tuple(gen(i) for i in range(n)) # shared buf and ibuf should be protected by locks.
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# zip_longest('ABCD', 'xy', fillvalue='-') --> ('A','x') ('B','y') ('C','-') ('D','-')
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def zip_longest(*args, fillvalue=None):
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iterators = [iter(it) for it in args]
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num_active = len(iterators)
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if not num_active:
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return
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yield acc
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for element in it:
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acc = func(acc, element)
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yield acc
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while True:
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values = []
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for i, it in enumerate(iterators):
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try:
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value = next(it)
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except StopIteration:
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num_active -= 1
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if not num_active:
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return
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iterators[i] = repeat(fillvalue)
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value = fillvalue
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values.append(value)
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yield tuple(values)
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# # Full analog of CPython builtin iter with 2 arguments
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# def iter(*args):
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#
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# if len(args) == 1:
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# return builtins.iter(args[0])
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#
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# class _iter:
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#
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# def __init__(self, args):
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# self.f, self.sentinel = args
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# def __next__(self):
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# v = self.f()
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# if v == self.sentinel:
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# raise StopIteration
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# return v
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#
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# return _iter(args)
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@ -1,3 +1,3 @@
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metadata(version="0.2.3")
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metadata(version="0.5.0")
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module("itertools.py")
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@ -1,24 +1,127 @@
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import itertools
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assert list(itertools.islice(list(range(10)), 4)) == [0, 1, 2, 3]
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assert list(itertools.islice(list(range(10)), 2, 6)) == [2, 3, 4, 5]
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assert list(itertools.islice(list(range(10)), 2, 6, 2)) == [2, 4]
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def g():
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while True:
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yield 123
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assert list(itertools.islice(g(), 5)) == [123, 123, 123, 123, 123]
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assert list(itertools.islice(itertools.cycle([1, 2, 3]), 10)) == [1, 2, 3, 1, 2, 3, 1, 2, 3, 1]
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assert list(itertools.islice(itertools.cycle(reversed([1, 2, 3])), 7)) == [3, 2, 1, 3, 2, 1, 3]
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assert list(itertools.starmap(lambda x, y: x * y, [[1, 2], [2, 3], [3, 4]])) == [2, 6, 12]
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# accumulate
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assert list(itertools.accumulate([])) == []
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assert list(itertools.accumulate([0])) == [0]
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assert list(itertools.accumulate([0, 2, 3])) == [0, 2, 5]
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assert list(itertools.accumulate(reversed([0, 2, 3]))) == [3, 5, 5]
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assert list(itertools.accumulate([1, 2, 3], lambda x, y: x * y)) == [1, 2, 6]
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assert list(itertools.accumulate([1,2,3,4,5], func=lambda x, y: x - y, initial=10)) == [10, 9, 7, 4, 0, -5]
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# chain
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assert list(itertools.chain()) == []
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assert list(itertools.chain([],[],[])) == []
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assert list(itertools.chain(range(3),[2*(i+1) for i in range(4)])) == [0, 1, 2, 2, 4, 6, 8]
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assert list(itertools.chain('abcd',[],range(5))) == ['a', 'b', 'c', 'd', 0, 1, 2, 3, 4]
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assert list(itertools.chain.from_iterable([])) == []
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assert list(itertools.chain.from_iterable(['ABC', 'DEF'])) == ['A', 'B', 'C', 'D', 'E', 'F']
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# combinations
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assert list(itertools.combinations('', 1)) == []
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assert list(itertools.combinations('ABCD', 0)) == [()]
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assert list(itertools.combinations('ABCD', 1)) == [('A',), ('B',), ('C',), ('D',)]
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assert list(itertools.combinations('ABCD', 3)) == [('A', 'B', 'C'), ('A', 'B', 'D'), ('A', 'C', 'D'), ('B', 'C', 'D')]
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assert list(itertools.combinations('ABCD', 4)) == [('A', 'B', 'C', 'D')]
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assert list(itertools.combinations('ABCD', 5)) == []
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assert len(list(itertools.combinations(range(7), 4))) == 35
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assert len(set(itertools.combinations(range(7), 4))) == 35
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# combinations with replacement
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assert list(itertools.combinations_with_replacement('ABCD', 0)) == [()]
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assert list(itertools.combinations_with_replacement('ABCD', 1)) == [('A',), ('B',), ('C',), ('D',)]
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assert list(itertools.combinations_with_replacement('ABC', 2)) == [('A', 'A'), ('A', 'B'), ('A', 'C'), ('B', 'B'), ('B', 'C'), ('C', 'C')]
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assert list(itertools.combinations_with_replacement('ABC', 3)) == [('A', 'A', 'A'), ('A', 'A', 'B'), ('A', 'A', 'C'), ('A', 'B', 'B'), ('A', 'B', 'C'), ('A', 'C', 'C'), ('B', 'B', 'B'), ('B', 'B', 'C'), ('B', 'C', 'C'), ('C', 'C', 'C')]
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# compress
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assert tuple(itertools.compress('ABCDEF', (1,0,1,0,1,1))) == ('A', 'C', 'E', 'F')
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assert tuple(itertools.compress('ABCDEF', (1,0,1,1,0))) == ('A', 'C', 'D')
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# count
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it = itertools.count(4, 3)
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for _ in range(200):
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n = next(it)
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assert list(next(it) for _ in range(5)) == [604, 607, 610, 613, 616]
|
||||
|
||||
# cycle
|
||||
it = itertools.cycle(iter('abcde'))
|
||||
assert list(next(it) for _ in range(12)) == ['a', 'b', 'c', 'd', 'e', 'a', 'b', 'c', 'd', 'e', 'a', 'b']
|
||||
it = itertools.cycle([2, 4, 'x'])
|
||||
assert list(next(it) for _ in range(7)) == [2, 4, 'x', 2, 4, 'x', 2]
|
||||
|
||||
# dropwhile
|
||||
assert list(itertools.dropwhile(lambda x: x<5, [1,4,6,4,1])) == [6, 4, 1]
|
||||
assert list(itertools.dropwhile(lambda x: ord(x)<118, '')) == []
|
||||
assert list(itertools.dropwhile(lambda x: ord(x)<118, 'dropwhile')) == ['w', 'h', 'i', 'l', 'e']
|
||||
|
||||
# filterfalse
|
||||
assert list(itertools.filterfalse(lambda x: ord(x)<110, 'dropwhile')) == ['r', 'o', 'p', 'w']
|
||||
|
||||
# groupby
|
||||
assert list(((k,''.join(g)) for k,g in itertools.groupby('aaaabbbccdaa'))) == [('a', 'aaaa'), ('b', 'bbb'), ('c', 'cc'), ('d', 'd'), ('a', 'aa')]
|
||||
|
||||
# islice
|
||||
assert ''.join(itertools.islice('', 2, 5)) == ''
|
||||
assert ''.join(itertools.islice('abcdefgh', 2, 5)) == 'cde'
|
||||
assert ''.join(itertools.islice('abcdefghij', 2, None, 3)) == 'cfi'
|
||||
assert ''.join(itertools.islice('abcdefghij', 2, None)) == 'cdefghij'
|
||||
assert ''.join(itertools.islice('abcdefghij', 6)) == 'abcdef'
|
||||
assert ''.join(itertools.islice('abcdefghij', 6, 6)) == ''
|
||||
assert list(itertools.islice(range(10), 2, 6, 2)) == [2, 4]
|
||||
assert list(itertools.islice(itertools.cycle([1, 2, 3]), 10)) == [1, 2, 3, 1, 2, 3, 1, 2, 3, 1]
|
||||
|
||||
# pairwise
|
||||
assert list(itertools.pairwise(range(5))) == [(0, 1), (1, 2), (2, 3), (3, 4)]
|
||||
assert list((''.join(t) for t in itertools.pairwise('abcdefg'))) == ['ab', 'bc', 'cd', 'de', 'ef', 'fg']
|
||||
assert list((''.join(t) for t in itertools.pairwise('ab'))) == ['ab']
|
||||
assert list((''.join(t) for t in itertools.pairwise('a'))) == []
|
||||
assert list((''.join(t) for t in itertools.pairwise(''))) == []
|
||||
|
||||
# permutations
|
||||
assert list(itertools.permutations('', 1)) == []
|
||||
assert list((''.join(t) for t in itertools.permutations('a', 2))) == []
|
||||
assert list((''.join(t) for t in itertools.permutations('abcd', 0))) == ['']
|
||||
assert list((''.join(t) for t in itertools.permutations('ab', 2))) == ['ab', 'ba']
|
||||
assert list((''.join(t) for t in itertools.permutations('abcd', 2))) == ['ab', 'ac', 'ad', 'ba', 'bc', 'bd', 'ca', 'cb', 'cd', 'da', 'db', 'dc']
|
||||
assert list(itertools.permutations(range(3))) == [(0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), (2, 1, 0)]
|
||||
|
||||
# product
|
||||
assert list(itertools.product()) == [()]
|
||||
assert list(itertools.product(range(2), repeat=0)) == [()]
|
||||
assert list((''.join(t) for t in itertools.product('ABC', 'xy'))) == ['Ax', 'Ay', 'Bx', 'By', 'Cx', 'Cy']
|
||||
assert list((''.join(t) for t in itertools.product('A', 'xy', repeat=2))) == ['AxAx', 'AxAy', 'AyAx', 'AyAy']
|
||||
assert list((''.join(map(str,t)) for t in itertools.product(range(2), repeat=3))) == ['000','001','010','011','100','101','110','111']
|
||||
|
||||
# repeat
|
||||
assert list(itertools.repeat(10, 0)) == []
|
||||
assert list(itertools.repeat(10, 1)) == [10]
|
||||
assert list(itertools.repeat(10, 3)) == [10, 10, 10]
|
||||
|
||||
# starmap
|
||||
assert list(itertools.starmap(pow, [])) == []
|
||||
assert list(itertools.starmap(pow, [(2,5), (3,2), (10,3)])) == [32, 9, 1000]
|
||||
assert list(itertools.starmap(lambda x, y: x * y, [[1, 2], [2, 3], [3, 4]])) == [2, 6, 12]
|
||||
|
||||
# takewhile
|
||||
assert list(itertools.takewhile(lambda x: x<5, [1,4,6,4,1])) == [1, 4]
|
||||
assert list(itertools.takewhile(lambda x: ord(x)<118, 'dropwhile')) == ['d', 'r', 'o', 'p']
|
||||
|
||||
# tee
|
||||
def genx(n):
|
||||
i=1;
|
||||
while True:
|
||||
yield i; i+=1
|
||||
if i >n:
|
||||
return
|
||||
it1, it2, it3 = itertools.tee(genx(1000), 3); _ = next(it1) # case of iterable that is unique; iterate once
|
||||
assert [min(it1), max(it2), sum(it3)] == [2, 1000, 500500]
|
||||
it1, it2, it3 = itertools.tee(range(2,10), 3); _ = next(it1) # iterable that is not unique; iterate once
|
||||
assert [min(it1), max(it2), sum(it3)] == [3, 9, 44] # the min is increased, other iterators remained full
|
||||
|
||||
# zip_longest
|
||||
assert list(itertools.zip_longest('', '')) == []
|
||||
assert list(itertools.zip_longest('', '', fillvalue='-')) == []
|
||||
assert list(itertools.zip_longest('', 'xy')) == [(None, 'x'), (None, 'y')]
|
||||
assert list(itertools.zip_longest('', 'xy', fillvalue='-')) == [('-', 'x'), ('-', 'y')]
|
||||
assert list(itertools.zip_longest('ABCD', 'xy', fillvalue='-')) == [('A','x'),('B','y'),('C','-'),('D','-')]
|
||||
|
||||
|
|
|
|||
Ładowanie…
Reference in New Issue