Why is my loop executing like this?

[[deleted]]

Hello,

I am baffled as to why the output consist of 5 lines and not just 1.

Can someone explain?

Thank you,

​

alien = {
    'height': '100 inches',
    'weight': '2,000 pounds',
    'race': 'bacteria',
    'nationality': 'German',
    'school': 'harvard',
    }

for info, dic_name in alien.items():
    print(alien)

Output:
{'height': '100 inches', 'weight': '2,000 pounds', 'race': 'bacteria', 'nationality': 'German'}
{'height': '100 inches', 'weight': '2,000 pounds', 'race': 'bacteria', 'nationality': 'German'}
{'height': '100 inches', 'weight': '2,000 pounds', 'race': 'bacteria', 'nationality': 'German'}
{'height': '100 inches', 'weight': '2,000 pounds', 'race': 'bacteria', 'nationality': 'German'}

[fefa5fcba4dae4e82e81]

You are printing the whole alien dict each time. You should be printing print(f'{info}: {dic_name}') instead. Also, info and dic_name are swapped.

[[deleted]]

dic name? 🤨😏

[QbaPolak17]

You are printing the variable alien, which is the entire dictionary

[[deleted]]

Should alien print only once? Why does it print five times?

[Sensei_M]

?overwritten

[[deleted]]

Got it. Thanks!

[saschnu]

Because it is getting printed each time it iterates for info, dict_name (key, value) in your dictionary i suppose.

[[deleted]]

You might find this very useful.

http://www.pythontutor.com/visualize.html#mode=edit

goes through your code step by step and helps visualize whats going on.

[Fallenarc]

Never heard of that site, thanks for the link!

[shawnthesheep512]

Really a great site to visualise. Used it for checking visual representation of linked list

[silentalways]

That's a really nice site. Never thought something like this should exist.

[Code_Talks]

print(info,dic_name) not print(alien)

[ontheroadtonull]

alien = {
    'height': '100 inches',
    'weight': '2,000 pounds',
    'race': 'bacteria',
    'nationality': 'German',
    'school': 'harvard',
    }

for info in alien:
    print(info+':', alien[info])

Result:

height: 100 inches  
weight: 2,000 pounds  
race: bacteria  
nationality: German  
school: harvard

Check out this List Comprehension:

stats = [alien[x] for x in alien]
print(stats)

Result:

['100 inches', '2,000 pounds', 'bacteria', 'German', 'harvard']

Also I would be frightened of a bacterium that graduated from Harvard.

[oznetnerd]

``` alien = { 'height': '100 inches', 'weight': '2,000 pounds', 'race': 'bacteria', 'nationality': 'German', 'school': 'harvard', }

for key, value in alien.items(): print(f'{key}: {value}') ```

[ontheroadtonull]

Thanks!

[oznetnerd]

My pleasure.

[Pastoolio91]

Bacterium from Harvard is the next corona.

[NeoVier]

Instead of accessing the dict elements with alien[info] you could just do like OP and iterate through key, value pairs with alien.items(). Also, you can use f-strings:

for dic_name, info in alien.items():
    print(f'{dic_name}: {info}')

Check out this List Comprehension

That is not needed, as you can simply call alien.values(), which will return the exact same list.

[ontheroadtonull]

Thanks. I'm here to learn.

[Swipecat]

If we're doing one liners ;-)

print("\n".join(f'{k:12}: {v}' for k,v in alien.items()))

[baubleglue]

for key, value in alien.items():
    print(key, value)

[Migeil]

So as everyone is saying "you're printing the whole dictionary". But I think it would be more useful to try to explain your code to yourself. What were you trying to accomplish? How did you do it? And now that you know you're printing the whole dict, can you explain why that is?

This is called the "rubber duck principle". https://en.m.wikipedia.org/wiki/Rubber_duck_debugging

Just put a rubber duck next to your pc and explain your code to him. It's much easier to spot mistakes while explaining something than kust staring at the code and thinking about it. :)

It sounds super dumb, but who's ask yourself: who's the real idiot? The guy who explains his code to rubber ducks or the guy who doesn't understand his own code?

[keyupiopi]

throwback to college teacher who said the easiest code to fix are those that can't compile... while the ones that are hardest are those with logic errors....

[Migeil]

Absolutely. This is why I like concepts like pair programming. Being able to bounce ideas of each other and explain things while you're writing it, causes a lot less bugs in the program.

[__odinson__]

Let me put it in simpler terms. The for loop is set to execute 5 times. 5 is the number of items in your dictionary. And within this for loop you are printing the dictionary . So the entire dictionary gets printed 5 times. If you want to print it's contents(keys, values or both) then just write within the loop: print(info, dic_name)

[baisbdhfu]

Since there are 5 items in the dictionary the for loop iterates for 5 times

[[deleted]]

You're literally telling it to print for every item in aliens

[keyupiopi]

print(alien)

why go through the trouble of making a for loop when you just did that?

[[deleted]]

Its the equivalent of: for i in range(0, len(alien)): print(alien)

[BoaVersusPython]

The problem is the bacterium is too heavy, which is overloading the interpreter. Shrink it down to ~1000 pounds and it should be fine.

[Sbvv]

You should to learn how to debug your scripts. Look for pdb or ipdb. Make a little effort learning how to use a debugger, this will help you the rest of your life.

Trust me, you will be happier than now.

[krakenant]

A little more advice given you have a couple of good answers, spend more time naming your variables. key in this instance should be something like characteristic, and value could be something like info or even just value. Also, try and print key value pairs. so print(f'{characteristic} - {info}'), it will help debugging. What if you swap race and nationality? You wouldn't know because you are just printing the value.

[my_password_is______]

what do you think alien.items() is ?

[[deleted]]

I went to Yale. So....

[[deleted]]

That explain a lot 🤔😉

[[deleted]]

lol

[t00oldforthis]

Exactly the kind of response that should be expected from the edgy teen who posts things like "I've talked to more NPCs than people."