dataafram colum or conditional code example

Example 1: make a condition statement on column pandas

df['color'] = ['red' if x == 'Z' else 'green' for x in df['Set']]

Example 2: if in df.columns

import pandas as pd

numbers = {'set_of_numbers': [1,2,3,4,5,6,7,8,9,10]}
df = pd.DataFrame(numbers,columns=['set_of_numbers'])

df['equal_or_lower_than_4?'] = df['set_of_numbers'].apply(lambda x: 'True' if x <= 4 else 'False')

print (df)