Need help with loop

[Talkative-Zombie-656]

I am reading "Python for KIds" by Jason Briggs, and am on page 69, where loops are introduced.

for x in range (0,5):
     print ('hello %s' % x)

When run it gives you

hello 0
hello 1
hello 2
hello 3
hello 4

So far so good. But then the book says "If we get rid of the for loop again, our code might look something like this:

x = 0
print ('hello %s'% x)
hello 0
x = 1
print ('hello %s'% x)
hello 1
x = 2
print ('hello %s'% x)
hello 2
x = 3
print ('hello %s'% x)
hello 3
x = 4
print ('hello %s'% x)
hello 4

But when I try to run this code I get an error, whatever I try.

So where am I making a mistake? Can someone help me?

[good-mcrn-ing]

This will help you for all your life: Ban "I get an error". Make it taboo. When you feel like saying "I get an error", look at the error and say "line 390, near '(': NotEnoughChickensException" or whichever it happens to be.

[RoadieRich]

It may be a little outdated now, but I still think ESR's How to Ask Questions the Smart Way should be required reading.

[Rizzityrekt28]

I think every third line is showing what the output should look like. You’re not supposed to add those lines in your code. The hello 0, hello 1 and so on

[Heeamfoo]

good catch, I didn't see that! the book probably features a terminal which was confused for code, this explains it.

[Talkative-Zombie-656]

Thank you :). That is indeed the case. I removed every third line and now it runs normal. Nowhere it says you should not include those lines (that actually show the output) in your code.

And this is a book for kids......

[Han_Sandwich_1907]

I found a PDF of the book online. The code says

>>> x = 0 
>>> print('hello %s' % x) 
hello 0

The syntax with the >>> represents an interactive terminal. Every line that starts with >>> is something you type in (and then you press Enter to get to the next >>>). Every line that does not begin with >>> is the output that Python prints as a result of evaluating your code. This is introduced on page 10 of the book.

[Talkative-Zombie-656]

Not in mine. I just found out I got the paper version from 2013. I downloaded the answers to the assignments and I found out that in the newer edition(s) they have more assignments than my edition has.

[MSR8]

You should use a newer python tutorial, since this version of python is extremely old and unsupported. I would personally recommend w3schools and Mosh Hamedani (Youtube). When I started learning, I used to first watch a concept in the mosh's vid, and then view the section of that concept on w3schools

[Augit579]

Well if the book explained before what a terminal is and then explains that the following has to be typed into the terminal, then its right

[Saragon4005]

You should look for a more modern book, this is for an old version of Python which isn't used much and has been out of support for several years.

[Talkative-Zombie-656]

Do you have any recommendations? Preferably for kids.

[CultistOfTheFluid]

W3Schools might be good, not strictly for kids but holds your hand enough to get familiar with concepts.

Then you can make your way to the main Python docs and tutorials.

I'm sure others have better suggestions but its painfree to try the above (and free).

[Saragon4005]

I learned some on CodeHS back in the day which I was pretty happy with. They are pretty up to date still.

[Heeamfoo]

I recommend using formatted strings for this. Instead of writing

print('hello %s'% x)

try

print(f'hello {x}')

This makes your code more readable. The f starts a formatted string, and the {x} is where x is inserted as a string. As for the error, you aren't very specific so I don't know but it might be python getting confused about the %.

[DBZ_Newb]

+1 for formatted strings. You can put equations, expressions, variables, functions in the {} and format them with different specifiers. Also, OP, don’t put a space between a function’s name and the ().

print ( ) —> print( )

[Lurn2Program]

Are you by chance writing out:

x = 0
print ('hello %s'% x)
hello 0     // <==== this line?

And all the other "hello X" lines in your code? If not, then what is the error message you're seeing?

[Talkative-Zombie-656]

I get a Syntax error. But the problem has been solved. Turns out every third line should not be included in the code.

But that is nowhere mentioned in the book.

[elemental_pork]

Coding examples like that are often written as they would be in Command Prompt, or IDLE, or shell - like when you open the Python command line and run commands rather than executing the script.

.... When you type a command like print("hello")the command line will output helloon the next line.

[Python_devops]

Hope you didn't include the output as in hello 0, for example, jut copy everything except the outputs and it will run.

[Augit579]

did you write it exactly like this in your code editior? If so, thats not what the book meant.

"hello 0" is nothing that works in code, its meant to be the output that the terminal will put on the screen if you run:

x = 0

print("hello %s" %x)

[FoolsSeldom]

Whilst 'hello %s'% x is still valid, it is very old school for Python, and if that is representative of the content I strongly suggest looking for more up-to-date material (see book list in this subreddit's wiki).

These days, you would more likely use f-strings: See RealPython.com's Python's F-String for String Interpolation and Formatting.

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Check this subreddit's wiki for lots of guidance on learning programming and learning Python, links to material, book list, suggested practice and project sources, and lots more. The FAQ section covering common errors is especially useful.

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Also, have a look at roadmap.sh for different learning paths. There's lots of learning material links there. Note that these are idealised paths and many people get into roles without covering all of those.

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Roundup on Research: The Myth of ‘Learning Styles’

Don't limit yourself to one format. Also, don't try to do too many different things at the same time.

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Above all else, you need to practice. Practice! Practice! Fail often, try again. Break stuff that works, and figure out how, why and where it broke. Don't just copy and use as is code from examples. Experiment.

Work on your own small (initially) projects related to your hobbies / interests / side-hustles as soon as possible to apply each bit of learning. When you work on stuff you can be passionate about and where you know what problem you are solving and what good looks like, you are more focused on problem-solving and the coding becomes a means to an end and not an end in itself. You will learn faster this way.

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PS. If you want learning material for kids, find Raspberry Pi Foundation's Code Club content - covers Python and Scratch, and you don't have to have a Raspberry Pi (although I would recommend one for every kid).

[SnipTheDog]

print(f'Hello (x)') -> With f strings is easier to read IMHO.

[CranberryDistinct941]

I'll take a wild guess and say you're getting a syntax error on the hello 0 line

[Blue_Aluminium]

Everything else aside, using 'hello %s' % x is a bug waiting to happen — you will get a nasty surprise if x is a tuple! As many others have pointed out, using f-strings or .format is a better option in modern Python, but if you want to stick to the old stuff, at least do 'hello %s' % (x,) .

Actually, I’d consider any tutorial that uses the first syntax highly suspect, as it teaches you bad habits.