set value of df in list comprehension code example

Example 1: pandas list comprehension

# Subtract 1 from row, for each row in df.year
df['previous_year'] = [row-1 for row in df['year']]

Example 2: comprehension list iloc pandas

df['Flag2'] = ["Increase" if x > y  else "Decrease" for (x,y) in zip(df['nextsalary'],df['prevsalary'])]