The correct answer is: A. Apply a function element-wise
The applymap
method in Pandas applies a function to each element of a DataFrame. This can be useful for performing operations such as converting data types, filtering rows, or calculating statistics.
The sort
method in Pandas sorts a DataFrame by a specified column or columns. This can be useful for reordering the rows of a DataFrame or for finding the maximum or minimum values in a column.
The reshape
method in Pandas reshapes a DataFrame into a different shape. This can be useful for converting a DataFrame from a long format to a wide format or vice versa.
The groupby
method in Pandas groups rows of a DataFrame by a specified column or columns. This can be useful for performing operations such as calculating statistics on groups of rows or for filtering rows based on their group.
Here is an example of how to use the applymap
method:
“`
import pandas as pd
df = pd.DataFrame({‘A’: [1, 2, 3], ‘B’: [4, 5, 6]})
df[‘C’] = df[‘A’].applymap(lambda x: x * 2)
print(df)
A B C
0 1 2
1 2 4
2 3 6
“`
In this example, the applymap
method is used to multiply each element in the A
column by 2. The result is a new column, C
, which contains the doubled values.