🔒 making text file | Python | Page 1

hybrid void Oct 28, 2025, 2:02 PM

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i want to implement a text file which contains atomic weigth data values, that i can use to later calculate weights of molecules. How would i go about this?

winter capeBOT Oct 28, 2025, 2:02 PM

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hybrid void i want to implement a text file which contains atomic weigth data values, that i...

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@hybrid void

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wispy karma Oct 28, 2025, 2:02 PM

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hybrid void i want to implement a text file which contains atomic weigth data values, that i...

Are you asking about how to make the text file? Or how to read it with python?

hybrid void Oct 28, 2025, 2:03 PM

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both id say

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how to make it and how to utilise it in my program

wispy karma Oct 28, 2025, 2:03 PM

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do you have examples of atomic weights?

hybrid void Oct 28, 2025, 2:04 PM

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H = 1.008
O = 15.999
C = 12.11

wispy karma Oct 28, 2025, 2:04 PM

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Ok great!

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If you had this as a string, do you know how you'd split it up into "element" and "value"?

"H = 1.008"

hybrid void Oct 28, 2025, 2:05 PM

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through a dictionary?

wispy karma Oct 28, 2025, 2:05 PM

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a dictionary would be great to hold the results, but we still need to "parse" the string

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we need a way to separate the element and weight out because right now it's just a single string

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atomic = "H = 1.008"

hybrid void Oct 28, 2025, 2:06 PM

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ive lowk not seen that before

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what would this do

wispy karma Oct 28, 2025, 2:06 PM

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You haven't seen a string before?

hybrid void Oct 28, 2025, 2:06 PM

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i have but not one with two = sings

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signs*

wispy karma Oct 28, 2025, 2:07 PM

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the 2nd equal sign is just part of the string

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it doesn't mean anything, it's just a literal =

hybrid void Oct 28, 2025, 2:07 PM

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oh its in " ic

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then .split(=) ?

wispy karma Oct 28, 2025, 2:07 PM

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exactly

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you could use whatever symbol you wanted really, as long as your consistent

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atomic = "H | 1.008"

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you could do this instead

hybrid void Oct 28, 2025, 2:07 PM

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ic

wispy karma Oct 28, 2025, 2:08 PM

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atomic = "H|1.008"

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H|1.008
O|15.999
C|12.11

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so if you have a text file that looks something like this, we can read the file line by line, split the |, then add a new key/value pair to a dictionary based on that result

hybrid void Oct 28, 2025, 2:09 PM

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ok ic

indigo mason Oct 28, 2025, 2:10 PM

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colon might look more natural in the text file though

hybrid void Oct 28, 2025, 2:10 PM

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how would i make a file?

wispy karma Oct 28, 2025, 2:10 PM

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or a comma, if we want to stick with more of a csv format

wispy karma Oct 28, 2025, 2:11 PM

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hybrid void how would i make a file?

you don't need to make the file with python

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make a new txt file on your computer and fill it in with the info

hybrid void Oct 28, 2025, 2:12 PM

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file_path = "new_file.txt"
with open(file_path, 'w') as file:
i read something like this, not examtly sure how it works. reason im asking is because duriong the exam im not sure ill be able to make oneseperately since ill be in a safe exam browser

wispy karma Oct 28, 2025, 2:12 PM

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perhaps you'll be provided the file then

hybrid void Oct 28, 2025, 2:12 PM

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ic

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is the with open function just a way of accessing an existing file then?

wispy karma Oct 28, 2025, 2:13 PM

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for now, just create the file and then I can show you how to read it

wispy karma Oct 28, 2025, 2:13 PM

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hybrid void is the with open function just a way of accessing an existing file then?

yup exactly

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open() is the function
with is a keyword for a context manager

hybrid void Oct 28, 2025, 2:14 PM

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i see thanks for the help, ill try to complete the rest of the program myself and will just post here if i get stuck

indigo mason Oct 28, 2025, 2:15 PM

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wispy karma or a comma, if we want to stick with more of a csv format

yes, only that it might be too visually similar to a period when reading it for a human to scan the content quickly

wispy karma Oct 28, 2025, 2:16 PM

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indigo mason yes, only that it might be too visually similar to a period when reading it for ...

valid point

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TSV it is 🙂

indigo mason Oct 28, 2025, 2:19 PM

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hybrid void i see thanks for the help, ill try to complete the rest of the program myself an...

this help thread will be automatically archived as read-only by the Python bot one hour after the last message was sent to the thread, so if it taks you longer then that you will either have to bump the thread before that until you are done with it, but often it's better to just open a new help thread instead if/when you need it

hybrid void Oct 28, 2025, 2:19 PM

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indigo mason this help thread will be automatically archived as read-only by the Python bot o...

ah i see thanks for the heads up

hybrid void Oct 28, 2025, 2:54 PM

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i tried the split method for the textfile but i get an error message when using the (,) for some reason:

with open(atoms_file, 'r') as file:
for line in file:
atom, weight = line.split(,)
atom_weights[atom] = float(weight)

wispy karma Oct 28, 2025, 2:55 PM

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strings always need "" around them

forest garden Oct 28, 2025, 2:56 PM

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hybrid void i have but not one with two = sings

If it's inside the string, so the "", it's just normal text.
The second = does not affect the code at all, think about it as a normal text.

So basically you have a variable, which is atomic and assigned a string/text to it.

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oh wait

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smh

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old message

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mb gng

hybrid void Oct 28, 2025, 2:57 PM

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wispy karma strings always need `""` around them

what do you mean

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like in this context

wispy karma Oct 28, 2025, 2:58 PM

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split() needs a string as its argument

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the thing you put inside the () is called an argument

hybrid void Oct 28, 2025, 2:58 PM

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oh i thought split meant what character signifies a split to be made

wispy karma Oct 28, 2025, 2:58 PM

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it does

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the character must be a string

hybrid void Oct 28, 2025, 2:58 PM

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so is line not an str in this scenario is what u mean?

wispy karma Oct 28, 2025, 2:59 PM

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if you want to split using a comma, it should be (",")

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you had (,)

hybrid void Oct 28, 2025, 2:59 PM

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oh ic

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oh now it works haha thanks

hybrid void Oct 28, 2025, 3:21 PM

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ok i think ive finished the calculations part of the program, however i get the error message
FileNotFoundError: [Errno 2] No such file or directory: 'atoms.txt'
when i run the program.

it says the problem is on this line:
with open(atoms_file, 'r') as file:

this is the previous line which im thinking might have something to do with it but im not sure:
atoms_file = "atoms.txt"
any ideas or should i send more of the code?

wispy karma Oct 28, 2025, 3:21 PM

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where is the atoms.txt file?

hybrid void Oct 28, 2025, 3:22 PM

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like right next to my python file in the vs code folder thingy

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theyre in the same folder

wispy karma Oct 28, 2025, 3:22 PM

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I don't use VSC, but I know it does some strange things regarding your cwd (current working directory)

hybrid void Oct 28, 2025, 3:22 PM

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oh so its supposed to work then?

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just some weird stuff thats specific to vsc

wispy karma Oct 28, 2025, 3:23 PM

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yeah, when you launch a program, relative files always need to be relative to your CWD

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usually it's set to whatever folder the file you're running is in

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you can force it with a little trick though

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import os

os.chdir(os.path.dirname(__file__))

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put this at the top of your file

hybrid void Oct 28, 2025, 3:26 PM

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oh sick

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now im getting keyErros 😭

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KeyError: 'H' no idea what this means tbh

wispy karma Oct 28, 2025, 3:34 PM

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do you know what a key is?

hybrid void Oct 28, 2025, 3:34 PM

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yh the first part of the dict

wispy karma Oct 28, 2025, 3:34 PM

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a key error is when you try and look up a key in a dict that doesn't exist

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!e

empty_dict = {}
print(empty_dict['H'])

winter capeBOT Oct 28, 2025, 3:34 PM

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wispy karma !e ```py empty_dict = {} print(empty_dict['H']) ```

:x: Your 3.14 eval job has completed with return code 1.

001 | Traceback (most recent call last):
002 |   File [35m"/home/main.py"[0m, line [35m2[0m, in [35m<module>[0m
003 |     print([31mempty_dict[0m[1;31m['H'][0m)
004 |           [31m~~~~~~~~~~[0m[1;31m^^^^^[0m
005 | [1;35mKeyError[0m: [35m'H'[0m

hybrid void Oct 28, 2025, 3:35 PM

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oh ic

wispy karma Oct 28, 2025, 3:35 PM

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now it's up to you to figure out why that might be the case

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print is your best friend for debugging things

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print out the dict and see why it might be missing that key

hybrid void Oct 28, 2025, 3:36 PM

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weird my dict is empty

wispy karma Oct 28, 2025, 3:37 PM

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now work backwards

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add some prints where you would expect to see them

hybrid void Oct 28, 2025, 3:37 PM

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im printing right after i first add to them

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atom_weights[atom] = float(weight) where atom_weights is the dict

wispy karma Oct 28, 2025, 3:37 PM

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print out some variables. Always think in your head "I expect it to look like this" and if it doesn't match what you think, you need to work backwards to figure out what might be the issue

wispy karma Oct 28, 2025, 3:37 PM

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hybrid void atom_weights[atom] = float(weight) where atom_weights is the dict

show your full code

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!paste

winter capeBOT Oct 28, 2025, 3:37 PM

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Pasting large amounts of code

If your code is too long to fit in a codeblock in Discord, you can paste your code here:
https://paste.pythondiscord.com/

After pasting your code, save it by clicking the Paste! button in the bottom left, or by pressing CTRL + S. After doing that, you will be navigated to the new paste's page. Copy the URL and post it here so others can see it.

hybrid void Oct 28, 2025, 3:38 PM

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import os

os.chdir(os.path.dirname(file))
def m_mass(molecule):
atom_weights = {}
atoms_file = "atoms.txt"
with open(atoms_file, 'r') as file:
for line in file:
atom, weight = line.split(",")
atom_weights[atom] = float(weight)
print (atom_weights)
m_mass('C')

winter capeBOT Oct 28, 2025, 3:38 PM

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Hey @hybrid void!

Please edit your message to use a code block

```py
print('Hello, world!')
```

This will result in the following:

print('Hello, world!')```

wispy karma Oct 28, 2025, 3:38 PM

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use the paste link or add the discord markdown so I can properly read your code

hybrid void Oct 28, 2025, 3:39 PM

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!paste

winter capeBOT Oct 28, 2025, 3:39 PM

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Pasting large amounts of code

If your code is too long to fit in a codeblock in Discord, you can paste your code here:
https://paste.pythondiscord.com/

After pasting your code, save it by clicking the Paste! button in the bottom left, or by pressing CTRL + S. After doing that, you will be navigated to the new paste's page. Copy the URL and post it here so others can see it.

hybrid void Oct 28, 2025, 3:39 PM

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https://paste.pythondiscord.com/MBWQ

wispy karma Oct 28, 2025, 3:41 PM

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can you share the txt file too?

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my guess is you have a space before/after the comma

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although that shouldn't result in an empty dict...

rotund vault Oct 28, 2025, 3:41 PM

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hybrid void https://paste.pythondiscord.com/MBWQ

I had suggest change print(atom_weights) to return atom_weight for reusibility

wispy karma Oct 28, 2025, 3:41 PM

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perhaps you never saved the file

hybrid void Oct 28, 2025, 3:42 PM

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!p

winter capeBOT Oct 28, 2025, 3:42 PM

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Missing required argument

pep_number

wispy karma Oct 28, 2025, 3:42 PM

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yeah, you should only be generating this atom dict once

hybrid void Oct 28, 2025, 3:42 PM

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https://paste.pythondiscord.com/UEGA

wispy karma Oct 28, 2025, 3:42 PM

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you have = in the file, but you're trying to split using ,

hybrid void Oct 28, 2025, 3:43 PM

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oh

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it was

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a problem of not savingf

rotund vault Oct 28, 2025, 3:43 PM

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hybrid void https://paste.pythondiscord.com/UEGA

You can drop the files into the past thingy brother no need to type

wispy karma Oct 28, 2025, 3:44 PM

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hybrid void a problem of not savingf

but you also should not have a= in the txt file

hybrid void Oct 28, 2025, 3:44 PM

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yh i changed it to C,numbers

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and so on

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oh nice now it works ahhaha finally thanks for all the help

winter capeBOT Oct 28, 2025, 4:56 PM

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#🔒 making text file