There's a sample in pyelftools that does that: https://github.com/eliben/pyelftools/blob/master/examples/dwarf_decode_address.py

Specifically, finding the line for the address goes like this:

def decode_file_line(dwarfinfo, address):
    # Go over all the line programs in the DWARF information, looking for
    # one that describes the given address.
    for CU in dwarfinfo.iter_CUs():
        # First, look at line programs to find the file/line for the address
        lineprog = dwarfinfo.line_program_for_CU(CU)
        prevstate = None
        for entry in lineprog.get_entries():
            # We're interested in those entries where a new state is assigned
            if entry.state is None:
                continue
            if entry.state.end_sequence:
                # if the line number sequence ends, clear prevstate.
                prevstate = None
                continue
            # Looking for a range of addresses in two consecutive states that
            # contain the required address.
            if prevstate and prevstate.address <= address < entry.state.address:
                filename = lineprog['file_entry'][prevstate.file - 1].name
                line = prevstate.line
                return filename, line
            prevstate = entry.state
    return None, None