Python 3 - Can pickle handle byte objects larger than 4GB? -

-

based on comment , referenced documentation, pickle 4.0+ python 3.4+ should able pickle byte objects larger 4 gb.

however, using python 3.4.3 or python 3.5.0b2 on mac os x 10.10.4, error when try pickle large byte array:

>>> import pickle >>> x = bytearray(8 * 1000 * 1000 * 1000) >>> fp = open("x.dat", "wb") >>> pickle.dump(x, fp, protocol = 4) traceback (most recent call last):   file "<stdin>", line 1, in <module> oserror: [errno 22] invalid argument

is there bug in code or misunderstanding documentation?

here simple workaround issue 24658. use pickle.loads or pickle.dumps , break bytes object chunks of size 2**31 - 1 in or out of file.

import pickle import os.path  file_path = "pkl.pkl" n_bytes = 2**31 max_bytes = 2**31 - 1 data = bytearray(n_bytes)  ## write bytes_out = pickle.dumps(data) open(file_path, 'wb') f_out:     idx in range(0, n_bytes, max_bytes):         f_out.write(bytes_out[idx:idx+max_bytes])  ## read bytes_in = bytearray(0) input_size = os.path.getsize(file_path) open(file_path, 'rb') f_in:     _ in range(0, input_size, max_bytes):         bytes_in += f_in.read(max_bytes) data2 = pickle.loads(bytes_in)  assert(data == data2)

Comments

Post a Comment

Popular posts from this blog

c# - Better 64-bit byte array hash -

-
i need hash algorithm produces 64-bit hash code ( long ) fewer collisions string.gethashcode() , fast (no expensive calls cryptographic functions). here's implementation of fnv still shows 3% of collisions after testing 2 million random strings. need number way lower. void main() { const string chars = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz!#@$%^&*()_+}{\":?><,./;'[]0123456789\\"; const int n = 2000000; var random = new random(); var hashes = new hashset<long>(); int collisions = 0; for(int = 0; < n; i++) { var len = random.next(chars.length); var str = new char[len]; (int j = 0; j < len; j++) { str[j] = chars[random.next(chars.length)]; } var s = new string(str); if(!hashes.add(get64bithash( s ))) collisions++; } console.writeline("collision percentage after " + n + " random strings: " + ((doubl
Read more

webrtc - Which ICE candidate am I using and why? -

-
[questions in bold below] i have setup kurento media server 5.1.3 in datacenter behind firewall running os ubuntu 14.04. has 2 network cards: 222.222.222.222 (eth0 - private ip) 111.111.111.111 (eth1 - public ip) attached below sdp (setremotedescription) when browser connected kurento media server type: answer, sdp: v=0 o=- 5487318114793304426 0 in ip4 0.0.0.0 s=kurento media server c=in ip4 0.0.0.0 t=0 0 a=group:bundle audio video m=audio 59068 rtp/savpf 111 0 c=in ip4 111.111.111.111 a=rtpmap:111 opus/48000/2 a=rtpmap:0 pcmu/8000 a=sendrecv a=rtcp:59068 in ip4 111.111.111.111 a=rtcp-mux a=ssrc:669011897 cname:user39019747@host-6e83e4c2 a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time a=mid:audio b=as:20 a=ice-ufrag:ymdk a=ice-pwd:lylifk5ueqzpwm91ddj37e a=fingerprint:sha-256 ff:0f:81:8c:41:4e:b4:b6:c6:d8:36:f3:d6:5f:09:fd:5f:af:13:b3:9d:fc:12:66:ac:f3:56:d6:5b:0a:73:5d a=candidate:1 1 udp 2013266431 111.111.111.111 55239 typ host a=candidate:2 1 udp
Read more

php - Zend Framework / Skeleton-Application / Composer install issue -

-
i trying create zend framework application using skeleton in netbeans. when run composer install, following error message: "c:\php\php.exe" "c:\composer\composer.phar" "--ansi" "--no-interaction" "update" "--dev" using deprecated option "dev". dev packages installed default now. loading composer repositories package information updating dependencies (including require-dev) requirements not resolved installable set of packages. problem 1 - package requires php >=5.5 php version (5.4.42) not satisfy requirement. problem 2 - installation request zendframework/zendframework 2.5.1 -> satisfiable zendframework/zendframework[2.5.1]. - zendframework/zendframework 2.5.1 requires php >=5.5 -> php version (5.4.42) not satisfy requirement. done. apparently, zend framework only needs php 5.3+ contradicts above. need use php 5.4. my composer.json following: { "name": "
Read more