how to insert new column and sum(), and make increase, decrase notif in my dataframe

i've data frame(df in pandas) below:

sector   Income Januari 2018     Income januari 2019     
1                  2000                    3000                  
1                  7000                    1000

and i want to insert new column with sum()

so my expected:

sector   Income Januari 2018     Income januari 2019   increase▲/decrease▼
1                  2000                    3000           1000 ▲ (green)         
1                  7000                    1000           6000 ▼ (red)

Solution

You can set background color by styles and export to excel:

def color(x): 
   c1 = 'background-color: green'
   c2 = 'background-color: red'
   c = ''
   m = x['Income januari 2019'] > x['Income Januari 2018']
   df1 = pd.DataFrame(c, index=x.index, columns=x.columns)
   df1['increase▲/decrease▼'] = np.where(m, c1, c2)
   return df1

df['increase▲/decrease▼'] = df['Income januari 2019'] - df['Income Januari 2018']
print (df)
   sector  Income Januari 2018  Income januari 2019  increase▲/decrease▼
0       1                 2000                 3000                 1000
1       1                 7000                 1000                -6000

df.style.apply(color,axis=None).to_excel('styled.xlsx', engine='openpyxl', index=False)

If need absolute values in output column add Series.abs:

df['increase▲/decrease▼'] = (df['Income januari 2019'] - df['Income Januari 2018']).abs()
print (df)
   sector  Income Januari 2018  Income januari 2019  increase▲/decrease▼
0       1                 2000                 3000                 1000
1       1                 7000                 1000                 6000