CODEWITHSUNDEEP
python
C9 Fox
C9 Fox

Reputation: 17

CM to INCH Converting Program Python

Hello i am trying to make a converting program but i can't get it to work, I am going to convert multiply different things but i start with CM to INCH. I get error TypeError: unsupported operand type(s) for /: 'str' and 'float'. Here is some of the code:

   print('Press the number of the one you want to convert: ')
   number = input()
   inch = float(2.54)
   if number == '1':
       print('How many inch? ')
       print('There are %s'.format(number / inch))

Here is the whole code:

print('Welcome to the converting program')
print('What of these do you want to convert?')
print(  "\nHow many centimeters in inches? 1"
    "\nHow many milliliters in a pint? 2"
    "\nHow many acres in a square-mile? 3"
    "\nHow many pounds in a metric ton? 4"
    "\nHow many calories in a BTU? 5")

print('Press the number of the one you want to convert: ')

number = float(input()) 

inch = float(2.54)
if number == '1':
    print('How many inch? ')
    print('There are {0}'.format(number / inch))

elif number == '2':
    print('millimeters')

elif number == '3':
    print('acres')

elif number == '4':
    print('pounds')

elif number == '5':
    print('calories')

Upvotes: 1

Views: 2219

Answers (2)

JamoBox
JamoBox

Reputation: 766

%s is the notation for formatting a string, %f should be used for floats. In newer versions of python however you should use {0}

print('There are {0}'.format(number / inch))

Read PEP 3101 for more information on this.

Further to this, as Sebastian Hietsch mentioned in his answer, your input variable is a string that will need to be converted to a float first. Do this before your formatting expression.

number = float(input())
inch = float(2.54)

You may want to add some error handling:

try:
    number = float(input())
except TypeError as e:
    print('input must be a float')
inch = float(2.54)

Of course, you will need to remove the quotes from the '1' in the if statement.

Upvotes: 1

Sebastian Hietsch
Sebastian Hietsch

Reputation: 474

The problem is that number is a string and you can't perform mathematical operations on it. What you'll need to do is convert it to an integer or a float using int(number) or float(number). So you could do: print("There are ℅f".format(float(number)/inch))

Upvotes: 0

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