How to enter parameters into a function when using pandas apply

First time posting here - have decided to try and learn how to use python whilst on Covid-19 forced holidays.

I'm trying to summarise some data from a pretty simple database and have been using the value_counts function.

Rather than running it on every column individually, I'd like to loop it over each one and return a summary table. I can do this using df.apply(pd.value_counts) but can't work out how to enter parameters into the the value counts as I want to have dropna = False.

Basic example of data I have:

# Import libraries 
import pandas as pd 
import numpy as np

# create list of winners and runnerup
data = [['john', 'barry'], ['john','barry'], [np.nan,'barry'], ['barry','john'],['john',np.nan],['linda','frank']] 

# Create the pandas DataFrame 
df = pd.DataFrame(data, columns = ['winner', 'runnerup']) 

# print dataframe. 
df

How I was doing the value counts for each column:

#Who won the most?
df['winner'].value_counts(dropna=False)

Output:
john     3
linda    1
barry    1
NaN      1
Name: winner, dtype: int64

How can I enter the dropna=False when using apply function? I like the table it outputs below but want the NaN to appear in the list.

#value counts table
df.apply(pd.value_counts)
      winner    runnerup
barry   1.0       3.0
frank   NaN       1.0
john    3.0       1.0
linda   1.0       NaN

#value that is missing from list
#NaN    1.0       1.0

Any help would be appreciated!!

Solution

You can use df.apply, like this:

df.apply(pd.value_counts, dropna=False)