Extract all files from a .tar.gz after wget and rename them

Question

Is there any easy way extract all files from a .tar.gz and rename the files upon extraction? The tars inside look like:

file1.obj
file2.xr
file3.ty
file4.hjg

All files are different extensions, but I want extract them and rename them the same, so the extracted files would be

name.obj
name.xr
name.ty
name.hjg

I know the names of all these files, and their extensions, are constant for all tar balls. I could easily extract them and then rename them after by searching for their name but that would be a heavy operation, is there an easier way? Here's my python script code

# GRAB DATES
#   range : 2010 - 2011
start_date = datetime(2010, 01, 01)
end_date = datetime(2011, 12, 31)

for date in daterange(start_date, end_date):
    file_append = static_path + "%04d" % date.year + "%02d" % date.month + "%02d" % date.day + ".tar.gz" 
    file_out = "%04d" % date.year + "%02d" % date.month + "%02d" % date.day

    # get tarball from site
    proc_wget = "wget -nd -O " + "%04d" % date.year + "/" + file_out + \
            ".tar.gz" + " http://water.weather.gov/precip/p_download_new/" + \
            "%04d" % date.year + "/" + "%02d" % date.month + "/" + \
            "%02d" % date.day + "/" + file_append

    # name of tarball is file_out + ".tar.gz" 
    # all files inside tarbal are static_name.*
    # so they all have the same name but different extensions
    extract = ["7z e " + file_out + ".tar.gz", 
               "7z x " + file_out + ".tar -o" ]
    os.system(proc_wget)
    os.system(extract[0])
    os.system(extract[1])

Answer 1

This should do the job:

$ tar -xzvf foo.tar && cd foo
$ for i in *; do echo $i |sed -re "s/[A-Za-z0-9]+(.*)/name\1/"; done

To do this in Python call:

new_str = re.sub('[A-Za-z]+(.*)', r'\name\1', old_str);

Here's another:

$ for i in *; do echo name.${i#*.}; done