Dictionary code problem.

Question

#Write a function called stars that takes in two dictionaries:
# - movies: a dictionary where the keys are movie titles and the values are lists of major performers in the movie. For example: movies["The Dark Knight"] = ["Christian Bale", "Heath Ledger", "Maggie Gyllenhall", "Aaron Eckhart"] - tvshows: a dictionary where the keys are TV show titles and the values lists of major performers in the show. #For example: tvshows["Community"] = ["Joel McHale", "Alison Brie", "Danny Pudi", "Donald Glover", "Yvette Brown"] #The function stars should return a new dictionary. The keys of the new dictionary should be the performers' names, and the values for each key should be the list of shows and movies in which that performer has appeared. Sort the shows and movies alphabetically.
def stars(movies, tvshows):
result = {}
for (key,value) in movies.items():
for each_value in value:
if value not in result.keys():
result[value]= []
result[value].append(key)
for (key,value) in tvshows.items():
for each_value in value:
if value not in result.keys():
result[value]= []
result[value].append(key)
return result
movies = {"How to Be Single": ["Alison Brie", "Dakota Johnson",
"Rebel Wilson"], "The Lego Movie": ["Will Arnett", "Elizabeth Banks", "Alison Brie", "Will Ferrell"]}
tvshows = {"Community": ["Alison Brie", "Joel McHale", "Danny Pudi", "Yvette Brown",
"Donald Glover"], "30 Rock": ["Tina Fey", "Tracy Morgan", "Jack McBrayer",
"Alec Baldwin", "Elizabeth Banks"], "Arrested Development": ["Jason Bateman", "Will Arnett", "Portia de Rossi"]}
print(stars(movies, tvshows))
********************************************
I am getting error "TypeError: unhashable type: 'list' on line " if value not in result.keys():"
please advise

Answer 1

NG_ , there is only a small issue but with a big impact on the outcome. you mixed up 2 variable names. see the reworked code in the attached list:
https://code.sololearn.com/c6ydvx81wf1Y/?ref=app

Answer 2

https://code.sololearn.com/c7KuTVOrqrJJ/?ref=app

Answer 3

It would be better to save your code in the playground and link it to the question, it would be much easier to test.
The problem is you are trying to use a list as dictionary key. That is just not possible. The key should be the name of the star (a string).
Maybe you could avoid this confusion by better choosing your variable names, so you remember what they actually mean:
for movie, crew in movies.items():
for star in crew:
if star not in result.keys():
result[star]= []
result[star].append(movie)

Answer 4

Thank you Lothar for your input. I was struggling with this since yesterday.