I need help I create this dataframe:

And i need to create a new column with this function:
def pgto(x, num):
if x == "(i)":
return num
elif x == "(ii)":
return 750000.00
elif x == "(iii)":
return num * 0.7
else:
return 3000000.00
then i aplicate a multiple loop for:
for x in df_final["Tipo"]:
for num in df_final["Valor_float"]:
df_final["Pgto"] = pgto(x, num)
But the result was it:

What i should do?