Initial data commit

Task/Summarize-primes/Python/summarize-primes.py

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+'''Prime sums of primes up to 1000'''
+
+
+from itertools import accumulate, chain, takewhile
+
+
+# primeSums :: [(Int, (Int, Int))]
+def primeSums():
+    '''Non finite stream of enumerated tuples,
+       in which the first value is a prime,
+       and the second the sum of that prime and all
+       preceding primes.
+    '''
+    return (
+        x for x in enumerate(
+            accumulate(
+                chain([(0, 0)], primes()),
+                lambda a, p: (p, p + a[1])
+            )
+        ) if isPrime(x[1][1])
+    )
+
+
+# ------------------------- TEST -------------------------
+# main :: IO ()
+def main():
+    '''Prime sums of primes below 1000'''
+    for x in takewhile(
+            lambda t: 1000 > t[1][0],
+            primeSums()
+    ):
+        print(f'{x[0]} -> {x[1][1]}')
+
+
+# ----------------------- GENERIC ------------------------
+
+# isPrime :: Int -> Bool
+def isPrime(n):
+    '''True if n is prime.'''
+    if n in (2, 3):
+        return True
+    if 2 > n or 0 == n % 2:
+        return False
+    if 9 > n:
+        return True
+    if 0 == n % 3:
+        return False
+
+    def p(x):
+        return 0 == n % x or 0 == n % (2 + x)
+
+    return not any(map(p, range(5, 1 + int(n ** 0.5), 6)))
+
+
+# primes :: [Int]
+def primes():
+    ''' Non finite sequence of prime numbers.
+    '''
+    n = 2
+    dct = {}
+    while True:
+        if n in dct:
+            for p in dct[n]:
+                dct.setdefault(n + p, []).append(p)
+            del dct[n]
+        else:
+            yield n
+            dct[n * n] = [n]
+        n = 1 + n
+
+
+# MAIN ---
+if __name__ == '__main__':
+    main()