41 lines
1.2 KiB
Python
41 lines
1.2 KiB
Python
# Computer scientists love the Fibonacci sequence
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# [https://en.wikipedia.org/wiki/Fibonacci_sequence], possibly
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# described by Acharya Pingala in छन्दःशास्त्र (Chhandaḥśāstra).
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#
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# The basic definition is that the next item in the sequence
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# if the sum of the two preceding items, and the two initial
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# items and 0 and 1.
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#
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# We end up with [0, 1, 1, 2, 3, 5, 8, 13, ...]
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def fibbo(n):
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match n:
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case 0 | 1:
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return n
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case _:
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return fibbo(n-1) + fibbo(n-2)
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# For example: the first few items in the sequence:
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for n in range(36):
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print(n, fibbo(n))
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# A (nowadays) less commonly used way to construct the mapping
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# from n to fibbo(n) is to use the map function.
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# map returns a generator, and we call list to collect the numbers:
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sequence = list(map(fibbo, range(36)))
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print(sequence)
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# To split the work between multiple Python processes, we can
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# use the multiprocessing module:
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import multiprocessing
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pool = multiprocessing.Pool()
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sequence = pool.map(fibbo, range(36))
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print(sequence)
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# We may use 'with' to clean up the pool after we're done with
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# the workers:
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with multiprocessing.Pool(10) as pool:
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sequence = pool.map(fibbo, range(36))
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print(sequence)
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