If a dataframe is created using a 2D dictionary, then the column labels are formed from …………… .

1. dictionary's values
2. inner dictionary's keys
3. outer dictionary's keys
4. none of these

Which of the following can be used to specify the data while creating a DataFrame ?

1. Series
2. List of Dictionaries
3. Structured ndarray
4. All of these

The axis 1 identifies a DataFrame's …………… .

1. rows
2. columns
3. values
4. datatype

To get the number of elements in a dataframe, …………… attribute may be used.

1. size
2. shape
3. values
4. ndim