我有以下代码
def gen_primes():
D = {}
q = 2
while True:
if q not in D:
yield q
D[q * q] = [q]
else:
for p in D[q]:
D.setdefault(p + q, []).append(p)
del D[q]
q += 1
f = open("primes1.txt","w")
filen = 1
ran1 = 1
ran2 = 10000000
k = 1
for i in gen_primes():
if (k >= ran1) and (k <= ran2):
f.write(str(i) + "\n")
if k%1000000 == 0:
print k
k = k + 1
else:
ran1 = ran2 + 1
ran2 = ran2 + 10000000
f.close()
filen = filen + 1;
f = open("primes" + str(filen) + ".txt","w")
if k > 100000000:
break
f.close()
素数生成算法取自 Simple Prime Generator in Python
该程序出现内存错误
Traceback (most recent call last):
File "C:\Python25\Projects\test.py", line 43, in <module>
for i in gen_primes():
File "C:\Python25\Projects\test.py", line 30, in gen_primes
D.setdefault(p + q, []).append(p)
MemoryError
我正在尝试在一个文件中存储连续的 10,000,000 个素数。
最佳答案
这个素数生成器不使用太多内存。它也不是很快。
def gcd(a, b):
rem = a % b
while rem != 0:
a = b
b = rem
rem = a % b
return b
def primegen():
yield 2
yield 3
yield 5
yield 7
yield 11
accum = 2*3*5*7
out = file('tmp_primes.txt', 'w')
inp = file('tmp_primes.txt', 'r+')
out.write('0x2\n0x3\n0x5\n0x7\n0xb\n')
inp.read(20)
inpos = inp.tell()
next_accum = 11
next_square = 121
testprime = 13
while True:
if gcd(accum, testprime) == 1:
accum *= testprime # It's actually prime!
out.writelines((hex(testprime), '\n'))
yield testprime
testprime += 2
if testprime >= next_square:
accum *= next_accum
nextline = inp.readline()
if (len(nextline) < 1) or (nextline[-1] != '\n'):
out.flush()
inp.seek(inpos)
nextline = inp.readline()
inpos = inp.tell()
next_accum = int(nextline, 16)
next_square = next_accum * next_accum
def next_n(iterator, n):
"""Returns the next n elements from an iterator.
>>> list(next_n(iter([1,2,3,4,5,6]), 3))
[1, 2, 3]
>>> list(next_n(primegen(), 10))
[2, 3, 5, 7, 11, 13, 17, 19, 23, 29]
"""
while n > 0:
yield iterator.next()
n -= 1
关于python - 如何解决这个内存错误 - python,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/6012604/