OverflowError while sending large file via socket

[Ryniek90]

When i wanted to send an .iso file of 4GB length, i had traceback:
"OverflowError: requested number of bytes is more than a Python string 
can hold"

Sockets are being used in every network app, i.e: p2p progs (like 
BitTorrent), and exchanged data is often bigger than 4GB. So why i've 
had that Traceback? How many number of bytes Python string can hold?