Mastering Python Data Structures

What method would you use to add a new key-value pair to a Python dictionary?

• dictionary_name.add(new_key, new_value)

• dictionary_name.append(new_key, new_value)

• Use dictionary_name[new_key] = new_value.

• dictionary_name.insert(new_key, new_value)

How do you retrieve the value associated with a specific key in a dictionary?

• Access the value with 'key.value' in the dictionary.

• Use 'dictionary.get(key)' to retrieve the value.

• Invoke 'dictionary.fetch(key)' to obtain the value.

• Use 'dictionary[key]' to get the value.

Which function in NumPy creates an array filled with zeros?

• numpy.zeros

• numpy.ones

• numpy.full

• numpy.empty

What is the output of np.array([1, 2, 3]) + np.array([4, 5, 6])?

• [5, 6, 7]

• [4, 5, 6]

• [1, 2, 3, 4, 5, 6]

• [5, 7, 9]

How can you reshape a NumPy array from shape (2, 3) to (3, 2)?

• Use numpy.transpose(arr)

• Use arr.reshape(2, 3)

• Use numpy.reshape(arr, (3, 2))

• Use numpy.resize(arr, (3, 2))

What is the purpose of the 'groupby' function in Pandas?

• To filter out unwanted data entries.

• To group data for aggregation or analysis based on specific criteria.

• To merge multiple DataFrames into one.

• To sort data in ascending order.

How do you select a specific column from a Pandas DataFrame?

• df.select('column_name')

• df.get('column_name')

• df['column_name'] or df.column_name

• df.column('column_name')

What method would you use to drop rows with missing values in a DataFrame?

• Use the 'remove()' method.

• Use the 'delete()' method.

• Use the 'fillna()' method.

• Use the 'dropna()' method.

How can you filter a DataFrame to show only rows where a specific column's value is greater than a certain number?

• df[df['column_name'] > x]

• df['column_name'] < x

• df[df['column_name'] == x]

• df[df['column_name'] >= x]

What is the difference between .loc and .iloc in DataFrame indexing?

• .loc is used for filtering, .iloc is for sorting.

• .loc is position-based, .iloc is label-based.

• .loc is label-based, .iloc is position-based.

• Both .loc and .iloc are label-based.