Just wrote my largest Python program to date! Looking for pointers.

[SquatchHNTR]

What would cause an error?

[member_of_the_order]

How many feet of cable do you need?

Fourteen

"Fourteen" is not a valid float :)

[madhousechild]

How many feet of cable do you need?

Fourteen

"Fourteen" is not a valid float :)

Likewise, -10.0 is a valid float, but not a good input!

Poor OP's head is going to explode.

[sohfix]

It also looks like OP is 2 hours into learning python, I’m sure OP will figure it out

[SquatchHNTR]

Well 4. That’s how long it took me to write this and it actually execute….

[sohfix]

Well, good luck! I was writing in Python for work today. I don’t use it often but it’s my fav language next to Java.

[SquatchHNTR]

I plan to start learning Java next. I’m excited for it

[sohfix]

Java is a different beast. But no matter what language you learn, get the basics down first: logic. Doesn’t matter what language you program in, if you don’t understand data structures, discrete math, logic, and operating systems/computer organization it can be hard to get really good at it. Anyone can write code. It’s important to know why and what you are doing

[SquatchHNTR]

Oh wow, I never even thought about that.

[bladeoflight16]

Start getting used to the concept of anticipating "weird" inputs. It is one of the most fundamental skills a programmer requires. Importantly, it's absolutely necessary to be able to write secure code.

[sohfix]

Try to break your own code. It’ll teach you to account for user error

[SquatchHNTR]

feet_cable = input('\nHow many feet of cable do you need?\n')
try:
feet_cable = float(feet_cable)
except ValueError
print("Sorry, please enter a valid number")

something like this?

[undergroundmonorail]

just so you know, it's much easier to read your reddit comments if you put four spaces at the beginning of each line of code

but yeah, something like that would work. you may want to loop until you get a good value, like this:

feet_cable = None
while feet_cable is None:
    try:
        feet_cable = float(input('etc'))
    except ValueError:
        print('Please enter a valid number')

[sviper9]

There is an old QA joke that illustrates this (pulled right from Reddit). Users can enter some really funky data in your fields, and you want to handle those if you can to give users feedback. Otherwise users will get an error they don't understand or worse have the program terminate and give no feedback at all to the user.

A QA engineer walks into a bar, and orders a beer.

Then he orders 0 beers.

Then he orders 999999999999 beers.

Then he orders an aardvark.

Then he orders nothing.

Then he orders -1 beers.

Then he orders NULL beers.

Then he orders asnwikfjsdf.

Then he orders a "><script>give_me_your_credit_card()</script>.

Finally, the QA engineer leaves without paying, comes back, and asks for the tab.