What is the maximum size of variable in python?

See sys.maxsize: http://docs.python.org/library/sys.html

The largest positive integer supported by the platform’s Py_ssize_t type, and thus the maximum size lists, strings, dicts, and many other containers can have.

On my MacBook Pro with a 64-bit build of CPython, it's quite sensibly 263-1 bytes:

>>> import sys
>>> sys.maxsize
9223372036854775807
>>> 

While on my 32-bit Linux box, it's 2^31-1:

>>> import sys
>>> sys.maxsize

>>> 

In practice, of course, you're unlikely to be able to actually make use of objects this large, but you can expect to run into serious practical problems (like, say, being out of memory or taking forever to load/save objects from storage) before you hit the theoretical limits.

Python allow you to only take care about variable name and ignore it's
size because pyhton dynamicly allocate it
so what's the limit in the allocated size in the memory

Dec 31 '07 #1

En Mon, 31 Dec 2007 15:40:31 -0200, هنداوى <3D********@gmail.comescribi�:

Python allow you to only take care about variable name and ignore it's
size because pyhton dynamicly allocate it
so what's the limit in the allocated size in the memory

As big as would fit on available memory.

--
Gabriel Genellina

Dec 31 '07 #2

On Dec 31, 11:26�*am, "James Matthews" <:

However some Debuggers will not show you variable's that are too big!

On Dec 31, 2007 7:38 PM, Gabriel Genellina <:

En Mon, 31 Dec 2007 15:40:31 -0200, هنداوى<>
escribi�:

Python allow you to only take care about variable name and ignore it's
size because pyhton dynamicly allocate it
so what's the limit in the allocated size in the memory

As big as would fit on available memory.

Is that mean that i can deal with files with size more than 2GB only
if the available memory allow

Dec 31 '07 #3

On Dec 31, 4:05�*pm, "هنداوى"

On Dec 31, 11:26�*am, "James Matthews" <:

However some Debuggers will not show you variable's that are too big!

On Dec 31, 2007 7:38 PM, Gabriel Genellina <:

En Mon, 31 Dec 2007 15:40:31 -0200, هنداوى <>
escribi�:

Python allow you to only take care about variable name and ignore it's
size because pyhton dynamicly allocate it
so what's the limit in the allocated size in the memory

As big as would fit on available memory.

Is that mean that i can deal with files with size more than 2GB only
if the available memory allow

No, files can be often be dealt with in manageable
chunks. Instead of reading the entire file into
memory, often it suffices to read in a line at a
time.

Dec 31 '07 #4

En Mon, 31 Dec 2007 20:05:41 -0200, هنداوى <3D********@gmail.comescribi�:

On Dec 31, 11:26�*am, "James Matthews" <:

>However some Debuggers will not show you variable's that are too big!

On Dec 31, 2007 7:38 PM, Gabriel Genellina <>
wrote:

En Mon, 31 Dec 2007 15:40:31 -0200, هنداوى <>
escribi�:

Python allow you to only take care about variable name and ignore

it's

size because pyhton dynamicly allocate it
so what's the limit in the allocated size in the memory

As big as would fit on available memory.

Is that mean that i can deal with files with size more than 2GB only
if the available memory allow

To be more precise, that depends on the OS. On Windows there is a limit of
2GB adressable memory per process (this is unrelated to the amount of
physical memory). You may increase that limit to 3GB. I think Python can
handle all the memory the OS is able to provide.
But do you actually have to keep the whole file in memory?

--
Gabriel Genellina

Dec 31 '07 #5

In the darkest hour on Mon, 31 Dec 2007 20:53:28 -0200,
Gabriel Genellina

>Is that mean that i can deal with files with size more than 2GB only
if the available memory allow

To be more precise, that depends on the OS. On Windows there is a limit of
2GB adressable memory per process (this is unrelated to the amount of
physical memory).

That's the 32bit Windows limit only (afaik).

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Jan 4 '08 #6

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