How to rename columns that have the same name?
You can use this:

df.columns = ['Goods_1', 'Durable goods','Services','Exports', 'Goods_2', 'Services', 'Imports', 'Goods_3', 'Services']


or if you have too many columns:

cols = []
count = 1
for column in df.columns:
    if column == 'Goods':
        cols.append(f'Goods_{count}')
        count+=1
        continue
    cols.append(column)
df.columns = cols