title: Python file parsing, can't catch strings in new line
body: <p>So Parsing a large text file with 56,900 book titles with authors and a etext no.
  Trying to find the authors. By parsing the file.
   The file is a like this:</p>
  
  <pre><code>TITLE and AUTHOR                                                     ETEXT NO.
  
  Aspects of plant life; with special reference to the British flora,      56900
   by Robert Lloyd Praeger
  
  The Vicar of Morwenstow, by Sabine Baring-Gould                          56899
   [Subtitle: Being a Life of Robert Stephen Hawker, M.A.]
  
  Raamatun tutkisteluja IV, mennessä Charles T. Russell                    56898
   [Subtitle: Harmagedonin taistelu]
   [Language: Finnish]
  
  Raamatun tutkisteluja III, mennessä Charles T. Russell                   56897
   [Subtitle: Tulkoon valtakuntasi]
   [Language: Finnish]
  
  Tom Thatcher's Fortune, by Horatio Alger, Jr.                            56896
  
  A Yankee Flier in the Far East, by Al Avery                              56895
   and George Rutherford Montgomery
   [Illustrator: Paul Laune]
  
  Nancy Brandon's Mystery, by Lillian Garis                                56894
  
  Nervous Ills, by Boris Sidis                                             56893
   [Subtitle: Their Cause and Cure]
  
  Pensées sans langage, par Francis Picabia                                56892
   [Language: French]
  
  Helon's Pilgrimage to Jerusalem, Volume 2 of 2, by Frederick Strauss     56891
   [Subtitle: A picture of Judaism, in the century
    which preceded the advent of our Savior]
  
  Fra Tommaso Campanella, Vol. 1, di Luigi Amabile                         56890
   [Subtitle: la sua congiura, i suoi processi e la sua pazzia]
   [Language: Italian]
  
  The Blue Star, by Fletcher Pratt                                         56889
  
  Importanza e risultati degli incrociamenti in avicoltura,                56888
   di Teodoro Pascal
   [Language: Italian]
  
  The Junior Classics, Volume 3: Tales from Greece and Rome, by Various    56887
  
  
  ~ ~ ~ ~ Posting Dates for the below eBooks:  1 Mar 2018 to 31 Mar 2018 ~ ~ ~ ~
  
  TITLE and AUTHOR                                                     ETEXT NO.
  
  The American Missionary, Volume 41, No. 1, January, 1887, by Various     56886
  
  Morganin miljoonat, mennessä Sven Elvestad                               56885
   [Author a.k.a. Stein Riverton]
   [Subtitle: Salapoliisiromaani]
   [Language: Finnish]
  
  "Trip to the Sunny South" in March, 1885, by L. S. D                     56884
  
  Balaam and His Master, by Joel Chandler Harris                           56883
   [Subtitle: and Other Sketches and Stories]
  
  Susien saaliina, mennessä Jack London                                    56882
   [Language: Finnish]
  
  Forged Egyptian Antiquities, by T. G. Wakeling                           56881
  
  The Secret Doctrine, Vol. 3 of 4, by Helena Petrovna Blavatsky           56880
   [Subtitle: Third Edition]
  
  No Posting                                                               56879
  </code></pre>
  
  <p>Author name usually starts after "by" or when there is no "by" in line then author name starts after a comma ","...However the "," can be a part of the title if the line has a by.<br>
  So, I parsed it for by first then for comma. </p>
  
  <p>Here is what I tried:</p>
  
  <pre><code>def search_by_author():
  
      fhand = open('GUTINDEX.ALL')
      print("Search by Author:")
  
      for line in fhand:
          if not line.startswith(" [") and not line.startswith("TITLE"):
              if not line.startswith("~"):
                  words = line.rstrip()
                  words = line.lstrip()
                  words = words[:-6] 
                  if ", by" in words:
  
                      words = words[words.find(', by'):]
                      words = words[5:]
                      print (words)
  
                  else:
                      words = words[words.find(', '):]
                      words = words[5:]
                      if "," in words:
                          words = words[words.find(', '):]
                          if words.startswith(','):
                              words =words[words.find(','):]
                              print (words)
                          else:
                              print (words)
                      else:
                          print (words)
                  if " by" in words:
                      words = words[words.find('by')]
                      print(words)
  
  search_by_author()
  </code></pre>
  
  <p>However it can't seem to find the author name for lines like </p>
  
  <pre><code>Aspects of plant life; with special reference to the British flora,      56900
   by Robert Lloyd Praeger
  </code></pre>