change pandas method default parameter for whole jupyter notebook

Question

is there a way to change the default parameter of pandas.value_counts(dropna=False) method in a Jupyter notebook for all the occasions that it is called?

I have tried to use a wrapper function but would rather the default method

def my_value_counts(series, dropna=False, *args, **kwargs):
    return series.value_counts(dropna=dropna, *args, **kwargs)

Answer 1

In python, you can change the default signature of a function or method even for existing instances:

import pandas as pd
import numpy as np
import inspect

sr = pd.Series(np.random.choice([1, np.nan], 10))

# Default behavior
print(inspect.signature(sr.value_counts))
print(sr.value_counts())

# This is the trick
pd.Series.value_counts.__defaults__ = (False, True, False, None, False)

# New behavior
print(inspect.signature(sr.value_counts))
print(sr.value_counts())

Output:

(normalize: 'bool' = False, sort: 'bool' = True, ascending: 'bool' = False, bins=None, dropna: 'bool' = True) -> 'Series'

1.0    6
dtype: int64

(normalize: 'bool' = False, sort: 'bool' = True, ascending: 'bool' = False, bins=None, dropna: 'bool' = False) -> 'Series'

1.0    6
NaN    4
dtype: int64

Obviously, it works with pd.value_counts too:

pd.value_counts.__defaults__ = (False, True, False, None, False)
pd.value_counts(sr)

Output:

1.0    6
NaN    4
dtype: int64