I'm trying to install setuptools with no success so far. When I do

python3.3 ez_setup.py

I get the following error:

Extracting in /tmp/tmp6nn4cz
Traceback (most recent call last):
  File "ez_setup.py", line 370, in <module>
    sys.exit(main())
  File "ez_setup.py", line 367, in main
    return _install(tarball, _build_install_args(options))
  File "ez_setup.py", line 55, in _install
    tar = tarfile.open(tarball)
  File "/usr/local/lib/python3.3/tarfile.py", line 1571, in open
    raise ReadError("file could not be opened successfully")
tarfile.ReadError: file could not be opened successfully

I've been reading and it seems that zlib-devel was not installed when the python installation was done. However, I did uncomment line 358 on Modules/Setup to enable zlib before compiling and if I try to

import zlib

on python3.3 console it works. Also, in case it helps, here is the ldd python3.3:

# ldd `which python3.3`
    linux-vdso.so.1 =>  (0x00007fff79fda000)
    libpthread.so.0 => /lib64/libpthread.so.0 (0x00002b96092da000)
    libdl.so.2 => /lib64/libdl.so.2 (0x00002b96094f6000)
    libutil.so.1 => /lib64/libutil.so.1 (0x00002b96096fa000)
    libz.so.1 => /lib64/libz.so.1 (0x00002b96098fe000)
    libm.so.6 => /lib64/libm.so.6 (0x00002b9609b12000)
    libc.so.6 => /lib64/libc.so.6 (0x00002b9609d95000)
    /lib64/ld-linux-x86-64.so.2 (0x00002b96090bc000)

What can I do?