Use the count() method to return column-wise count of a DataFrame.
Example here is for count() as Regular Aggregate function. For count() as Time Series Aggregate, refer to count() in Time Series Aggregate Mode.
Example
>>> df = DataFrame("employee_info")
>>> df
first_name marks dob joined_date
employee_no
100 abcd None None None
101 abcde None None 1902-05-12
112 None None None 2018-05-12
>>> df1 = df.select(['employee_no', 'first_name', 'marks'])
>>> df1.count()
count_employee_no count_first_name count_marks
0 3 2 0