Using Panda For Comparing Column Values And Creating Column Based On The Values In Compared Columns?

I am very new to python and pandas. I have following example CSV as input. ID Name Activity 1 AB Play 2 AD Hurt 3 cd Polite 4 CA Play I want to transform this

Solution 1:

You can use factorize:

In [6]:
df['NumActivity'] = pd.factorize(df['Activity'])[0] +1
df

Out[6]:
   ID Name Activity  NumActivity
0   1   AB     Play            1
1   2   AD     Hurt            2
2   3   cd   Polite            3
3   4   CA     Play            1

Here factorize returns a tuple containing array pairs:

In [8]:
pd.factorize(df['Activity'])

Out[8]:
(array([0, 1, 2, 0]), Index(['Play', 'Hurt', 'Polite'], dtype='object'))

So we index the first element using [0] and seeing as you want your index to start from 1 we +1 to the values.