finding common movies and actors

#!/usr/bin/env python3

import sys

if len(sys.argv) < 3:
  print("\nUsage:")
  print("  ./find_common.py actor1 actor2")
  print("  ./find_common.py movie1 movie2\n")
  sys.exit(0)

one = sys.argv[1]
two = sys.argv[2]

def file_recall(filename,op,label):
  pattern = op + " |" + label + "> => "
  n = len(pattern)
  with open(filename,'r') as f:
    for line in f:
      if line.startswith(pattern):
        line = line[n:]
        return line[1:-1].split("> + |")
  return []

def display(line):
#  return ", ".join(line)
  return "\n".join(line)

def intersection(a,b):
  return list(set(a) & set(b))

imdb_sw = "sw-examples/improved-imdb.sw"    # our imdb data

def print_common_movies(sw_file,one,two):
  actor1 = "actor: " + one
  actor2 = "actor: " + two
  movies1 = file_recall(sw_file,"movies",actor1)
  movies2 = file_recall(sw_file,"movies",actor2)

# check if we have info on them:
  if len(movies1) == 0 or len(movies2) == 0:
    return

  common_movies = intersection(movies1,movies2)

  print()
  print("common movies for:")
  print(one)
  print(two)
  print("number of common movies:",len(common_movies))
  print("common movies:")
  print(display(common_movies))
  print()

def print_common_actors(sw_file,one,two):
  movie1 = "movie: " + one
  movie2 = "movie: " + two
  actors1 = file_recall(sw_file,"actors",movie1)
  actors2 = file_recall(sw_file,"actors",movie2)

# check if we have info on them:
  if len(actors1) == 0 or len(actors2) == 0:
    return

  common_actors = intersection(actors1,actors2)

  print()
  print("common actors for:")
  print(one)
  print(two)
  print("number of common actors:",len(common_actors))
  print("common actors:")
  print(display(common_actors))
  print()


print_common_actors(imdb_sw,one,two)
print_common_movies(imdb_sw,one,two)

$ ./find_common.py "Tom Cruise" "Nicole Kidman"

common movies for:
Tom Cruise
Nicole Kidman
number of common movies: 8
common movies:
movie: Eyes Wide Shut (1999)
movie: Days of Thunder (1990)
movie: Der Geist des Geldes (2007)
movie: August (2008)
movie: Boffo! Tinseltown's Bombs and Blockbusters (2006)
movie: Stanley Kubrick: A Life in Pictures (2001)
movie: Far and Away (1992)
movie: The Queen (2006)


$ ./find_common.py "Matt Damon" "Morgan (I) Freeman"

common movies for:
Matt Damon
Morgan (I) Freeman
number of common movies: 3
common movies:
movie: Invictus (2009)
movie: The People Speak (2009)
movie: Magnificent Desolation: Walking on the Moon 3D (2005)

$ ./find_common.py "Bruce Willis" "Tom Cruise"

common movies for:
Bruce Willis
Tom Cruise
number of common movies: 1
common movies:
movie: Boffo! Tinseltown's Bombs and Blockbusters (2006)

$ ./find_common.py "Bruce Willis" "Matt Damon"

common movies for:
Bruce Willis
Matt Damon
number of common movies: 1
common movies:
movie: Ocean's Twelve (2004)

$ ./find_common.py "Brad Pitt" "George Clooney"

common movies for:
Brad Pitt
George Clooney
number of common movies: 7
common movies:
movie: Burn After Reading (2008)
movie: Ocean's Twelve (2004)
movie: Boffo! Tinseltown's Bombs and Blockbusters (2006)
movie: Ocean's Eleven (2001)
movie: Touch of Evil (2011)
movie: Ocean's Thirteen (2007)
movie: Confessions of a Dangerous Mind (2002)

$ ./find_common.py "Matt Damon" "Ben Affleck"

common movies for:
Matt Damon
Ben Affleck
number of common movies: 10
common movies:
movie: Chasing Amy (1997)
movie: Jersey Girl (2004)
movie: Jay and Silent Bob Strike Back (2001)
movie: School Ties (1992)
movie: Glory Daze (1995)
movie: Dogma (1999)
movie: The Third Wheel (2002)
movie: Good Will Hunting (1997)
movie: Unite for Japan (2011)
movie: Field of Dreams (1989)

-- now find the common actors for the Ocean's series of movies:
$ ./find_common.py "Ocean's Eleven (2001)" "Ocean's Twelve (2004)"

common actors for:
Ocean's Eleven (2001)
Ocean's Twelve (2004)
number of common actors: 18
common actors:
actor: David (II) Sontag
actor: Casey Affleck
actor: Julia (I) Roberts
actor: Andy (I) Garcia
actor: George Clooney
actor: Eddie Jemison
actor: Elliott Gould
actor: Larry Sontag
actor: Matt Damon
actor: Carl Reiner
actor: Topher Grace
actor: Brad Pitt
actor: Scott L. Schwartz
actor: Scott Caan
actor: Bernie Mac
actor: Jerry (I) Weintraub
actor: Shaobo Qin
actor: Don Cheadle

$ ./find_common.py "Ocean's Twelve (2004)" "Ocean's Thirteen (2007)"

common actors for:
Ocean's Twelve (2004)
Ocean's Thirteen (2007)
number of common actors: 16
common actors:
actor: Don Cheadle
actor: Casey Affleck
actor: Elliott Gould
actor: Bernie Mac
actor: Matt Damon
actor: Brad Pitt
actor: Eddie Izzard
actor: Eddie Jemison
actor: George Clooney
actor: Scott Caan
actor: Jerry (I) Weintraub
actor: Scott L. Schwartz
actor: Carl Reiner
actor: Shaobo Qin
actor: Andy (I) Garcia
actor: Vincent Cassel