How to print every line of processing code in Python?

When testing or creating a new function, I often like to print every line of code that is happening so that I can see how every line is processing.

Is there a library or method that can serve this purpose? I'm looking for something more convenient so I don't have to type print after every line.

For example, instead of writing this function

def test_func():
    l = range(10)
    print l
    l = zip(l,range(30,40))
    print l 
    l = dict(l)
    print l 

I'd like to write this without writing print, yet still get every line printed

def test_func():
    l = range(10)
    l = zip(l,range(30,40))
    l = dict(l)

Perhaps there is a Python decorator or something for this?