Inverting a dictionary in Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an empty dictionary for the inverted result.

Python

inverted = [1]

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Adict()

B[]

Cset()

D{}

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets creates a list, not a dictionary.

Using set() creates a set, not a dictionary.

We use {} to create an empty dictionary in Python.

2fill in blank

medium

Complete the code to loop through the original dictionary's items.

Python

for key, value in original.[1]():
    inverted[value] = key

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Aitems

Bkeys

Cvalues

Diter

Attempts:

3 left

💡 Hint

Common Mistakes

Using keys() only gives keys, not values.

Using values() only gives values, not keys.

The items() method returns key-value pairs from a dictionary.

3fill in blank

hard

Fix the error in the code to invert the dictionary correctly.

Python

inverted = {}
for k, v in data.items():
    inverted[[1]] = k

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Av

Bk

Cdata

Dinverted

Attempts:

3 left

💡 Hint

Common Mistakes

Using k as the new key keeps the dictionary the same.

Using data or inverted as keys causes errors.

When inverting, the original value v becomes the new key.

4fill in blank

hard

Fill the four blanks to create a dictionary comprehension that inverts the dictionary.

Python

inverted = { [1]: [2] for [3], [4] in original.items() }

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Avalue

Bkey

Ck

Dv

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping keys and values incorrectly.

Using variable names inconsistently.

In a dictionary comprehension, the syntax is {new_key: new_value for key, value in dict.items()}. Here, v is the new key and k is the new value.

5fill in blank

hard

Fill all three blanks to invert the dictionary and handle duplicate values by storing keys in a list.

Python

inverted = {}
for [1], [2] in original.items():
    inverted.setdefault([3], []).append([1])

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Akey

Bvalue

Ck

Dv

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong variable names.

Not using setdefault to handle duplicates.

We use setdefault with the value v as key and append the original key k to handle duplicates.