_(7)

prev_len= 0
with open('inf_e_20101022_m_04_rendezve.txt', 'w') as f:
    for key in sorted(dl_w, key= len):
        if len(key)!=prev_len and prev_len!=0:
            f.write('\n')
        for word in dl_w[key][:-1]:
            f.write(word + ' ')
        f.write(dl_w[key][-1])
        f.write('\n')
        prev_len= len(key)