In Python, what is `sys.maxsize`?

Python can handle arbitrarily large integers in computation. Any integer too big to fit in 64 bits (or whatever the underlying hardware limit is) is handled in software. For that reason, Python 3 doesn’t have a sys.maxint constant. The value sys.maxsize, on the other hand, reports the platform’s pointer size, and that limits the size of Python’s data … Read more

memory error in python

This one here: seems to be very inefficient and expensive for large strings. Better do A buffer object keeps a reference to the original string and start and length attributes. This way, no unnecessary duplication of data occurs. A string of length l has l*l/2 sub strings of average length l/2, so the memory consumption would roughly be l*l*l/4. With a … Read more

What does ** do in C language?

In C arguments are passed by values. For example if you have an integer varaible in main and the following function then if you call the function in main like this then the parameter gets the value of variable x in main. However the parameter itself occupies a different extent in memory than the argument. So any … Read more

Python subprocess.Popen “OSError: [Errno 12] Cannot allocate memory”

As a general rule (i.e. in vanilla kernels), fork/clone failures with ENOMEM occur specifically because of either an honest to God out-of-memory condition (dup_mm, dup_task_struct, alloc_pid, mpol_dup, mm_init etc. croak), or because security_vm_enough_memory_mm failed you while enforcing the overcommit policy. Start by checking the vmsize of the process that failed to fork, at the time of the fork attempt, and then compare to the amount of free memory (physical and swap) as it … Read more