User Select Temperature Conversion Python Program – Part 2 - Python Tutorial

User Select Temperature Conversion Python Program – Part 2

In this Python tutorial, we will improve our program we built-in the previous tutorial called user select temperature conversion Python program. This is a great opportunity to see how to work through your program to address issues and limit the amount of time troubleshooting your program after release. Recall that it is always important to trouble shoot your programs over and over before you release it. If you release a program that contains issues in the world, then you will spend more time handling support than you would working on your next project.

Functions and Methods In This Python Tutorial

• print()


• input()


• if statement


• .lower()


• .strip()


• .format()


• float()


• round()


• slice [0]

Issues with our Program

We saw some issues in our first Python program that would have made our program less desirable to our users.  First issue we saw was that the user would have to capitalize celsius or fahrenheit and prior experience, I know users are unlikely to use the shift key when they want a quick answer. Second issue we saw was if the user inputs the wrong command in the code would still run and then return an error which is not good practice if the program fails then the user should know why right away. Issue three if the user spelled fahrenheit or celsius wrong the program would fail that is not the right idea users would be turned off and never use our program. Let’s look at the issues and work through them and fix them

Code From Version 1.0 Of Our Program

#Code From Version 1.0 Of Our Program

print('Welcome To Our Temp Conversion Program')
temp = input("What temp would you like to convert to? Type Celsius or Fahrenheit. ")
userstemp = float(input("What is your temp to be converted. "))

if temp == 'Celsius':
	cel = round((userstemp - 32) * 5 / 9, 1)
	print("Your temp in Celsius is ".format(cel))
elif temp == 'Fahrenheit':
	fah = round(userstemp * 9 / 5 + 32, 1)
	print("Your temp in Fahrenheit is ".format(fah))
else:
	print("Whoops Something went wrong")

Fixing The Issues in Version 1.0

We need to fix this program so it runs flawlessly when we release the program to our clients. Our goal is to make the program more user friendly and reliable.

Issue 1

Issue 1 –  The program runs even if the user gives us the wrong command

If the user gives us the wrong command in our second line of code then line third line will still run and then kick back an error.  This is not good practice if the user does something wrong they should be alerted right away.

The Fix

We can fix issue 1 by moving the third line of our code which asks the user to input the current temperature into the if statement. We will now use this line twice once in the if statement and once in the elif statement.This ensures our code will only work when the user inputs the correct command.

The Code 

#issue 1 code

print('Welcome To Our Temp Conversion Program')
temp = input("What temp would you like to convert to? Type Celsius or Fahrenheit. ")


if temp == 'Celsius':
 userstemp = float(input("What is your temp to be converted. "))
	cel = round((userstemp - 32) * 5 / 9, 1)
	print("Your temp in Celsius is ".format(cel))
elif temp == 'Fahrenheit':
 userstemp = float(input("What is your temp to be converted. "))
	fah = round(userstemp * 9 / 5 + 32, 1)
	print("Your temp in Fahrenheit is ".format(fah))
else:
	print("Whoops Something went wrong")

Tip: Any time you make changes to your program I suggest you run the program so you can locate any issues that may arise from the code changes. If the program does not work then you will know the problem code.

Issue 2

Issue 2 – If the user does not capitalize Celsius or Fahrenheit then the program will fail

When the user types in a command in our current code they must capitalize the first letter.  In my prior experience users do not necessarily do so. This will cause the program to fail and this would not be good for our business. User’s would think we build crappy programs and go to our competition which would not be a good idea.

The Fix

We can easily fix this problem using .lower() string method which will make the users input lowercase which will give us the ability to anticipate the user’s input.  If we use the .lower() string method then we need to change our if and elif statements so that our code has celsius and fahrenheit in lowercase so it matches the users input.

The Code

#issue 2 code

print('Welcome To Our Temp Conversion Program')
temp = input("What temp would you like to convert to? Type Celsius or Fahrenheit. ").lower()

if temp == 'celsius':
 userstemp = float(input("What is your temp to be converted. "))
	cel = round((userstemp - 32) * 5 / 9, 1)
	print("Your temp in Celsius is ".format(cel))
elif temp == 'fahrenheit':
 userstemp = float(input("What is your temp to be converted. "))
	fah = round(userstemp * 9 / 5 + 32, 1)
	print("Your temp in Fahrenheit is ".format(fah))
else:
	print("Whoops Something went wrong")

Issue 3

Issue 3 – If the user uses a space in our code then the code will fail

If the user uses a space in front of the command or after the command then our code will fail and once again we will want to avoid this.

The Fix

To ensure that the user does not use a space in front of command or after the command, we need to use a string method called .strip() this will remove the spaces before and after the command.

The Code

#issue 3 code

print('Welcome To Our Temp Conversion Program')
temp = input("What temp would you like to convert to? Type Celsius or Fahrenheit. ").lower().strip()

if temp == 'celsius':
 userstemp = float(input("What is your temp to be converted. "))
	cel = round((userstemp - 32) * 5 / 9, 1)
	print("Your temp in Celsius is ".format(cel))
elif temp == 'fahrenheit':
 userstemp = float(input("What is your temp to be converted. "))
	fah = round(userstemp * 9 / 5 + 32, 1)
	print("Your temp in Fahrenheit is ".format(fah))
else:
	print("Whoops Something went wrong")

Issue 4

Issue 4 – If the user spells the command wrong code will fail

If the user misspells celsius or fahrenheit wrong then our code will fail.  We want to think of ways a user could make our code fail and avoid the scenario at all cost.

The Fix

We could use a slice on the user’s input to get just the users first letter. Since the two commands start with different letters, we can avoid spelling mistakes by getting the users first letter and running the code based off that. We indicate a slice with square brackets[ ] and then we put zero in the square brackets which says we want the first letter of the users command.  We will need to change if and elif statements to c and f since we just want the first letter.

The Code

#Issue 4 Code

print('Welcome To Our Temp Conversion Program')
temp = input("What temp would you like to convert to? Type Celsius or Fahrenheit. ").lower().strip()


if temp[0] == 'c':
	userstemp = float(input("What is your temp to be converted. "))
	cel = round((userstemp - 32) * 5 / 9, 1)
	print("Your temp in Celsius is ".format(cel))
elif temp[0] == 'f':
	userstemp = float(input("What is your temp to be converted. "))
	fah = round(userstemp * 9 / 5 + 32, 1)
	print("Your temp in Fahrenheit is ".format(fah))
else:
	print("Whoops Something went wrong")

Conclusion

We have now updated our program to version 1.1 which is now more user friendly and less likely to break when our clients use our program. I have a tendency to build programs like this I will first build one so I can get the result I want and then I will work my way through the program fixing issues that may arise. I will concentrate on the users experience, program speed and reliability. If we can fix all the issues in our program before we release the program we will live a happy life.

If you have any questions about User Select Temperature Conversion Python Program leave a comment below and we will do our best to help you out.

User Select Temperature Conversion Python Program – Part 2