The recipes also show patternsįor using itertools with the operator and collections modules as The recipesĪlso give ideas about ways that the tools can be combined - for example, howĬompress() and range() can work together. Various ways of thinking about individual tools - for example, thatĬom_iterable is related to the concept of flattening. The primary purpose of the itertools recipes is educational. 各 iterable の要素をまとめるイテレータを作成します。iterable の長さが違う場合、足りない値は fillvalue で埋められます。最も長い itarable が尽きるまでイテレーションします。およそ次と等価です:ĭef zip_longest ( * args, fillvalue = None ): # zip_longest('ABCD', 'xy', fillvalue='-') -> Ax By C- D- iterators = num_active = len ( iterators ) if not num_active : return while True : values = for i, it in enumerate ( iterators ): try : value = next ( it ) except StopIteration : num_active -= 1 if not num_active : return iterators = repeat ( fillvalue ) value = fillvalue values. zip_longest ( * iterables, fillvalue = None ) ¶ Raised when using simultaneously iterators returned by the same tee()Ĭall, even if the original iterable is threadsafe. popleft () return tuple ( gen ( d ) for d in deques )
Multi-line report may list a name field on every third line).ĭef tee ( iterable, n = 2 ): it = iter ( iterable ) deques = def gen ( mydeque ): while True : if not mydeque : # when the local deque is empty try : newval = next ( it ) # fetch a new value and except StopIteration : return for d in deques : # load it to all the deques d. Can be used to extract related fields fromĭata where the internal structure has been flattened (for example, a Unlike regular slicing, islice() does not support negative values for If stop is None, then iterationĬontinues until the iterator is exhausted, if at all otherwise, it stops at the One which results in items being skipped. Non-zero, then elements from the iterable are skipped until start is reached.Īfterward, elements are returned consecutively unless step is set higher than Make an iterator that returns selected elements from the iterable. id )) def _grouper ( self, tgtkey, id ): while self.
currvalue = object () def _iter_ ( self ): return self def _next_ ( self ): self. Zip_longest('ABCD', 'xy', fillvalue='-') -> Ax By C- D-ĪA AB AC AD BA BB BC BD CA CB CC CD DA DB DC DD
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