Quadratic calculator - First code

[Windows9]

First time coding. It basically calculates the nth term for a simple quadratic sequence. Are there any ways I can make it better

number1 = float(input("Number 1"))
number2 = float(input("Number 2"))
number3 = float(input("Number 3"))
number4 = float(input("Number 4"))
number5 = float(input("Number 5"))
sequence = [number1, number2, number3, number4, number5]
print(sequence)

#Calculating difference 1
dif1num1 = number2 - number1
dif1num2 = number3 - number2
dif1num3 = number4 - number3
dif1num4 = number5 - number4

#Calculating difference 2

dif2num1 = dif1num2 - dif1num1
dif2num2 = dif1num3 - dif1num2
dif2num3 = dif1num4 - dif1num3
dif_array = [dif2num1, dif2num2, dif2num3]
print(dif_array)
#Confirming quadratic

valid1 = int(0)
valid2 = int(0)
valid3 = int(0)

if dif2num1 and dif2num2 == dif2num3:
    valid3 = valid3 + 1

if valid3 == 0:
  print("The sequence is not quadratic")

var_ns = dif2num1 / 2

one_n_squared_1 = 1
one_n_squared_2 = 4
one_n_squared_3 = 9
one_n_squared_4 = 16
one_n_squared_5 = 25

new_n_squared_1 = one_n_squared_1 * var_ns
new_n_squared_2 = one_n_squared_2 * var_ns
new_n_squared_3 = one_n_squared_3 * var_ns
new_n_squared_4 = one_n_squared_4 * var_ns
new_n_squared_5 = one_n_squared_5 * var_ns

diff1 = number1 - new_n_squared_1
diff2 = number2 - new_n_squared_2

dif_01 = dif2num1 / 2
dif_02 = str(dif_01)
dif_03 = (dif_02 + "n squared")


diff_final = diff2 - diff1
diff_final_str = str(diff_final)
print(dif_03 + "+" + diff_final_str + "n")

 

[Sauron]

You could accept inputs in a loop and place them in a list rather than assign a distinct variable to each of them. This would also allow you to expand your program to a sequence of arbitrary length. In the same way you could generate the powers of each integer programmatically, in a list.

 

Also all the "new" variables are redundant, you could have just run the multiplication while declaring the "old" ones.

[AbydosOne]

(caveat emptor, I speak C-like languages better than Python)

10 minutes ago, Windows9 said:

if dif2num1 and dif2num2 == dif2num3

 

I suspect in this line you mean...

if dif2num1 == dif2num3 and dif2num2 == dif2num3

... otherwise you might just be checking if dif2num1 is not 0 (at least in C it works that way; Python might just be that smart).

 

-----

 

On a higher level: using a loop to run through your first array to validate the first and create the second array (so your input data could be arbitrary length), and another loop to validate the second and create the third (etc.), and then another loop to validate the third.

 

Loops are your friend, especially in work like this. It also makes fixing algorithmic mistakes much quicker because you don't need to change n-lines of code every time, just one.

[BobVonBob]

I'm suspecting this is python? If so, you don't need float on the numbers or int on the valids, python will take care of that for you and convert where necessary.

 

You don't appear to be using valid1 or valid2, so those aren't necessary.

 

if dif2num1 and dif2num2 == dif2num3:

This is casting dif2num1 and dif2num2 to booleans, and with floats that means that what this is actually saying is

if (dif2num1 != 0.0) and (dif2num2 != 0.0) == (dif2num3 != 0.0):

What I suspect you want is for all three to be equal, which would instead be represented as

if dif2num1 == dif2num2 == dif2num3:

 

dif_01 = dif2num1 / 2
dif_02 = str(dif_01)
dif_03 = (dif_02 + "n squared")

Mixing variables with the same naming style but totally different data types can get confusing fast. Python also does a lot of easy conversion with strings, so you could write this whole block as

dif_03 = (dif2num1 / 2 + "n squared")

 

 

And as others have mentioned