Find NaN rows

Data in a table can be None or NaN (not a number). Pandas has a function isna that for each element in the table, is True if the element is missing (None or NaN) or False otherwise.

Consider the table

import pandas as pd

df = pd.DataFrame({'count': [np.NaN, 2], 'fruit': ['apple', None]})
count fruit
1 np.NaN apple
2 2 None

Task: Write a function, na_rows(df) which takes in the DataFrame, df and returns only the rows that have at least one missing (None or NaN) element.

Example Input

Code to generate input

df = pd.DataFrame({'count': [np.NaN, 2, 3], 'fruit': ['apple', None, 'orange']})


Table generated

count fruit
0 nan apple
1 2
2 3 orange

Example Output

count fruit
0 nan apple
1 2