not-in-pandas 0.1.1

A package that adds the notin method to pandas.Series and pandas.DataFrame objects

not-in-pandas

Adds notin method to pandas.Series and pandas.DataFrame objects. Returns exactly the same as negating isin.

Installation

Use pip to install not-in-pandas.

pip install not-in-pandas

Usage

import pandas as pd
import not_in_pandas

# on Series
>>> s = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama', 'hippo'], name='animal')
>>> s.notin(['cow', 'lama'])

0    False
1    False
2    False
3     True
4    False
5     True
Name: animal, dtype: bool


# on DataFrame
>>> df = pd.DataFrame(
...   {
...    "animal_a": ["lama", "cow", "lama", "beetle", "lama"],
...    "animal_b": ["cow", "beetle", "cow", "hippo", "lama"]
...   }
... )

>>> df.notin(['cow', 'lama'])

   animal_a  animal_b
0     False     False
1     False      True
2     False     False
3      True      True
4     False     False
5      True      True

Why this isn't already on Pandas?

Pandas core developers thought this method would be redundant, because you achieve the same results by negating a isin method ~Series.isin(['lama', 'cow']). And main files on the Pandas package are already huge and difficult to navigate, so I understand their reluctancy on adding more unnecessary stuff.

I personally think this method:

• Improves readability a lot, specially with nested conditions
• Keeps consistency with other not methods like Series.notna or Series.notnull
• Is consistent with raw Python logic a not in b
• Makes starting programmers less annoyed because they don't find a method they think should exist (and avoids a Google search), specially if they know that .notna already exists
• I use .isin a lot