__getitem__ and __len__ in PyTorch - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the __len__ method that returns the size of the dataset.

PyTorch

def __len__(self):
    return [1]

Drag options to blanks, or click blank then click option'

Aself.data

Bself.length

Clen(self.data)

Dlen(self)

Attempts:

3 left

💡 Hint

Common Mistakes

Returning self.data directly instead of its length.

Using len(self) which causes infinite recursion.

The __len__ method should return the number of items in the dataset, which is the length of self.data.

2fill in blank

medium

Complete the code to define the __getitem__ method that returns the data item at the given index.

PyTorch

def __getitem__(self, index):
    return [1]

Drag options to blanks, or click blank then click option'

Aself.data.get(index)

Bself[index]

Cself.get(index)

Dself.data[index]

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to call self.get(index) which is not defined.

Using self[index] which causes recursion.

The __getitem__ method should return the item at index from self.data, which is a list or similar container.

3fill in blank

hard

Fix the error in the __getitem__ method to correctly return the label for the given index.

PyTorch

def __getitem__(self, index):
    data = self.data[index]
    label = self.labels[1]
    return data, label

Drag options to blanks, or click blank then click option'

A[index]

B(index)

C{index}

D.index

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses which calls the object as a function.

Using braces which is invalid syntax for indexing.

To access an element by index in a list, use square brackets []. So self.labels[index] is correct.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps each word to its length only if the length is greater than 3.

PyTorch

lengths = {word: [1] for word in words if len(word) [2] 3}

Drag options to blanks, or click blank then click option'

Alen(word)

B>

C<

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of > in the condition.

Mapping to word instead of its length.

The dictionary comprehension maps each word to its length using len(word). The condition filters words with length greater than 3 using >.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps each uppercase key to its value only if the value is positive.

PyTorch

result = [1]: [2] for k, v in data.items() if v [3] 0}

Drag options to blanks, or click blank then click option'

Ak.upper()

Bv

C>

Dk

Attempts:

3 left

💡 Hint

Common Mistakes

Using k instead of k.upper() for keys.

Using < instead of > in the condition.

The comprehension uses k.upper() to convert keys to uppercase, maps to value v, and filters for values greater than zero using >.