Pandas – How to append data to a column?

Likely makes sense to for loop this, but I don’t know what Pandas functions to use. I want to take data from one column and append it to another in parenthesis:

>Solution :

You can use an apply function that will work for each row:

df = pd.DataFrame({'col1': ['A', 'B'], 'col2': [1, 2]})
df.apply(lambda x: f'{x.col1} ({x.col2})', axis=1)

Or you could use a vectorized solution:

df['col1'] + ' (' + df['col2'].astype(str) + ')'