I am trying to gather an number amount from user input, convert it to a float, add commas to the float, and then convert it to a string again so I can print it using Python.
Here is my code:
usr_name = raw_input("- Please enter your name: ")
cash_amt = raw_input("- " + usr_name +", please enter the amount of money to be discounted: $")
discount_rate = raw_input("- Please enter the desired discount rate: ")
num_years = raw_input("- Please enter the number of years to discount: ")
npv = 0.0
usr_name = str(usr_name)
cash_amt = float(cash_amt)
cash_amt = round(cash_amt, 2)
cash_amt = "{:,}".format(cash_amt)
discount_rate = float(discount_rate)
num_years = float(num_years)
npv = float(npv)
discount_rate = (1 + discount_rate)**num_years
npv = round((cash_amt/discount_rate), 2)
npv = "{:,}".format(npv)
print "\n" + usr_name + ", $" + str(cash_amt) + " dollars " + str(num_years) + " years from now
at adiscount rate of " + str(discount_rate) + " has a net present value of $" + str(npv)
I am getting a "Unsupported operand type" tied to "npv = round((cash_amt/discount_rate), 2)" when I try to run it. Do I have to convert cash_amt back to a float after adding the commas? Thanks!
Your code can be shortened to the following:
usr_name = raw_input("- Please enter your name: ")
cash_amt = raw_input("- " + usr_name +", please enter the amount of money to be discounted: $")
discount_rate = raw_input("- Please enter the desired discount rate: ")
num_years = raw_input("- Please enter the number of years to discount: ")
# usr_name is already a string
cash_amt = float(cash_amt)
cash_amt = round(cash_amt, 2)
discount_rate = float(discount_rate)
num_years = int(num_years) # we want an int to print, discount_rate is a float so our calculations will be ok.
discount_rate = (1 + discount_rate)**num_years
npv = round((cash_amt/discount_rate), 2)
print "\n{}, ${:.2f} dollars {} years from now at discount rate of {:.2f} has a net " \
"present value of ${}".format(usr_name,cash_amt,num_years,discount_rate,npv)
npv = float(npv) is never actually used as you then do npv = round((cash_amt/discount_rate), 2) without using the first npv you assign a value to.
cash_amt = "{}".format(cash_amt) is causing your error so you can just remove it and do the formatting in your final print statement.