'''
For this exercise, you can use the following documentation: 
https://docs.python.org/3/tutorial/datastructures.html#dictionaries.

# Dictionaries

A dictionary is associative: it links a category to its components, or in 
Python-language, a key to its values. You can change a dictionary after it has 
been defined, i.e., it is mutable or changeable.

Make a dictionary which contains the words of a sentence as keys and the next 
word as value. For example, the sentence "Luke, I am your father" would 
correspond to the following dictionary:
'''

example_sentence_dictionary = {"Luke" : "I", 
                                "I" : "am", 
                                "am" : "your", 
                                "your" : "father"}

'''
Make a similar dictionary for the sentence: "if you can do it". Do so by 
defining an empty dictionary and progressively adding items.
'''

sentence_dictionary = {} # Define an empty dictionary

# You can add an item to the dictionary in the following way:
sentence_dictionary["if"] = "you"

'''
Now if we slightly change our sentence, we want to be able to remove a key and 
its value. The new sentence is: "you can do it".

Change the existing dictionary to reflect the change in the sentence. 
Use the `.pop()` method to remove an item. Between the brackets, you only have 
the include the key; `.pop()` will then remove both the key and its value.
'''

# Add your code here

print(sentence_dictionary)

'''
Now imagine you would want to see which word comes after "do" in the sentence. 
You can retrieve a value corresponding to a specific key by "indexing" the 
dictionary with that key. Try this yourself to see which word comes after "can". 
Also check what happens when you enter a key that is not in the dictionary at 
all; what kind of error do you get?
'''

word_after = sentence_dictionary["do"]
print(word_after)

'''
Making a sentence dictionary becomes more difficult if you have words that 
appear in the sentence multiple times. As a value can only contain one variable,
 you will need to use a list to have multiple words associated to one key. 
 For example, the sentence "It's the eye of the tiger" would become
'''

sentence_dictionary = {"It's" : ["the"], 
                       "the" : ["eye", "tiger"], 
                       "eye" : ["of"], 
                       "of" : ["the"]}

'''
Make such a dictionary yourself of the sentence "I drink coffee and I eat a pastry". 
Again, start from an empty dictionary and progressively add items. Remember: 
if you want to add an item to a list, you can use the method `.append()`.
'''

sentence_dictionary = {}
sentence_dictionary["I"] = ["drink"]