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[3.13] Simplify and speed-up an itertools recipe (gh-127848) (gh-127998)
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1 changed files with 6 additions and 6 deletions
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@ -1015,7 +1015,7 @@ The following recipes have a more mathematical flavor:
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.. testcode::
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def powerset(iterable):
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"powerset([1,2,3]) → () (1,) (2,) (3,) (1,2) (1,3) (2,3) (1,2,3)"
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# powerset([1,2,3]) → () (1,) (2,) (3,) (1,2) (1,3) (2,3) (1,2,3)
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s = list(iterable)
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return chain.from_iterable(combinations(s, r) for r in range(len(s)+1))
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@ -1104,11 +1104,6 @@ The following recipes have a more mathematical flavor:
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data[p*p : n : p+p] = bytes(len(range(p*p, n, p+p)))
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yield from iter_index(data, 1, start=3)
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def is_prime(n):
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"Return True if n is prime."
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# is_prime(1_000_000_000_000_403) → True
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return n > 1 and all(n % p for p in sieve(math.isqrt(n) + 1))
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def factor(n):
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"Prime factors of n."
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# factor(99) → 3 3 11
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@ -1123,6 +1118,11 @@ The following recipes have a more mathematical flavor:
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if n > 1:
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yield n
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def is_prime(n):
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"Return True if n is prime."
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# is_prime(1_000_000_000_000_403) → True
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return n > 1 and next(factor(n)) == n
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def totient(n):
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"Count of natural numbers up to n that are coprime to n."
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# https://mathworld.wolfram.com/TotientFunction.html
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