Trouble with Python 3

[Imada]

Hello,

Yesterday I was in doubt about which language to learn, and then i asked here, someone told me to learn Python.

So I started researching and found that to confuse me even more there is the python 2 and 3, but I thought "should not be much difference, I will learn the 3 because it is more complete"

At first everything was fine, I was following a tutorial for python 2, but until then was completely applicable in the python 3, except that the command "print" needs to be put in ( ), but until i could figure out that difference alone.

But now I encounter a problem, running this script:

# test.py - Calculator of expenses

print ("Balance of domestic expenses")
ana = input ('How many Ana spent?')
bia = input ('How many bia spent?')
total = float (ana) + float (bia)
print ('Total Expenses = R$ %s.') % total
average = total/2
print ('Expenses per person = R$ %s.') % average

When i run it on python 2 it runs fine, but on 3 i receive this error:

Balance of domestic expenses
How many Ana spent?3
How many bia spent?6
Total Expenses = R$ %s.
Traceback (most recent call last):
File "/home/eddie/Documentos/test.py", line 7, in <module>
print ('Total Expenses = R$ %s.') % total
TypeError: unsupported operand type(s) for %: 'NoneType' and 'float'

It seems to me the "%"is read differently in python 2 and 3 as in the "print", but I can not figure out a way around this, can someone help me?

[coopstah13]

perhaps python2 allows incorrect syntax for string formatting

%s is for string, you would want to use %f for float variable in string formatting

python 3 isn't "more complete", it is a new version of the language with newer and different features, python 2.x is more stable as it has been around a long time and is suitable for most people (also not all 3rd party works on 3)

[Imada]

Traceback (most recent call last):
File "/home/eddie/Documentos/test3.py", line 6, in <module>
print ('Avegare Expenses = R$ %f.') % total
TypeError: unsupported operand type(s) for %: 'NoneType' and 'float'

%f. doesn't work neighter...

So i guess it's better to begin with python 2 instead of 3?

[coopstah13]

so, apparently for some reason total is interpreted as being null, i'm not sure why this would happen based on what your code is

unless ' changes meaning in python3, i was pretty sure in python2 you could use them for strings, but i never use them, always use "

try changing your print to use " instead of '

[coopstah13]

i figured it out, i loaded up python 3

('Total Expenses = R$ %s.') % total

should be

('Total Expenses = R$ %s.' % total)

[Imada]

now it's allright! Thanks coopstah!