CODEWITHSUNDEEP
pythondictionary
Jonerhan
Jonerhan

Reputation: 97

Python: Dictionary in a Dictionary

This is my program so far. What I need to do is written in the docString. 

#string, list, list --> Dictionary
def addMovie (title, charList, actList):
    """The function addMovie takes a title of the movie, a list of characters,
    and a list of actors. (The order of characters and actors match one
    another). The function addMovie adds a pair to myIMDb. The key is the title
    of the movie while the value is a dictionary that matches characters to
    actors"""

    dict2 = {}
    for i in range (0, len(charList)):
        dict2 [charList[i]] = actList[i]

    myDict = {title, dict2}
    return myDict

The Dictionary myIMBd is currently empty. But what I need help with is the loop. When I try to do this in the runner.

addMovie("Shutter Island", ['Teddy Daniels','Crazy Lady'],['Leodnardo diCaprio', 'old actress'] )

I get an error that says 

Traceback (most recent call last):
File "<pyshell#2>", line 1, in <module>
addMovie("Shutter Island", ['Teddy Daniels','Crazy Lady'],['Leodnardo diCaprio', 'old actress'] )
File "C:\Python33\makeDictionary.py", line 10, in addMovie
myDict = {title, dict2}
TypeError: unhashable type: 'dict'

Does that mean that I can't have a dictionary inside of a dictionary? If so, how do I change it from a dictionary to a non-dict. If I can have a dict inside a dict, why doesn't this work.

Upvotes: 0

Views: 145

Answers (5)

Robᵩ
Robᵩ

Reputation: 168616

As others pointed out, you said , when you should have said :.

Having said that, this version also works, but doesn't require the loop:

def addMovie (title, charList, actList):
    return { title : dict(zip(charList, actList)) }

Upvotes: 0

Aditya
Aditya

Reputation: 3158

This is what you want :

  def addMovie (title, charList, actList):
    dict2 = {}
    myDict={}
    for i in range (0, len(charList)):
        dict2 [charList[i]] = actList[i]
    myDict[title] = dict2
    return myDict

  #printed for testing
  print addMovie("Shutter Island", ['Teddy Daniels','Crazy Lady'],['Leodnardo diCaprio', 'old actress'] )

Upvotes: 0

oleg
oleg

Reputation: 4182

this is not dict, rather set

myDict = {title, dict2}

You should use colon to create dict

myDict = {title: dict2}

But this exception can be related to dict in dict too

TypeError: unhashable type: 'dict'

If You try to use dict as key of other dict or as item of set You wil get this error

Upvotes: 1

SethMMorton
SethMMorton

Reputation: 48725

You are creating a set. Use this instead

myDict = {title: dict2}

A dict in python is not hashable, and the requirement for something to be in a set is that it is hashable (that's how you can quickly tell from the error message what you did wrong). With the commas and no :, what you wrote is the set literal notation.

Also, dict keys must be hashable, but that's not your issue.

Upvotes: 2

Christian Ternus
Christian Ternus

Reputation: 8492

You want something like:

myDict = {title: dict2}

What you've provided is actually Python's set literal.

Upvotes: 2

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