Subtracting values between two dictionaries/ floating point numbers

[FloppyPoppy]

You can and should use f-string everywhere,eg your line 8.
Also think of line length,line 8 is now 215 characters in length.
PEP-8 say 79 characters line length,but i would say that 90'ish is okay.
Example:

user_purchase_location = 'Mall'
most_profitable_resourse = 'Diamond' 
profit_sorted = '99'
user_sale_destination = 'Gold Shop'

print(
f"The most profitable item to buy at {user_purchase_location} is {most_profitable_resourse}\n\
and will make a net profit of {profit_sorted} per unit when sold at {user_sale_destination}"
)

Output:
The most profitable item to buy at Mall is Diamond
and will make a net profit of 99 per unit when sold at Gold Shop

Thanks for that information i will be sure to try and incorporate F strings going forward. I have changed the program to reflect your advice.

Here is how the code is looking now

#### taking user information
user_purchase_location = input(f"Where are you planning to buy your goods?").lower()
user_sale_destination = input(f"Where are you planning to sell your goods?").lower()

#### dicts of items available to buy and sell at locations along with UEC price.
buying_olisar = {'Medical Supply': 17.01,}
selling_olisar = {'Agricium': 25.60, 'Aluminum': 1.25, 'Beryl': 4.26, 'Chlorine': 1.57, 'Corundum': 2.53, 'Diamond': 6.90, 'Distilled Spirits': 4.95, 'Fluorine': 2.80, 'Gold': 6.07, 'Hydrogen': 1.02, 'Iodine': 0.41, 'Laranite': 28.91, 'Processed Food': 1.39, 'Quartz': 1.44, 'Scrap': 1.67, 'Stims': 3.40, 'Titanium': 8.27, 'Tungsten': 3.90,}
buying_levski = {'Agricultural Supply': 1.11, 'Aluminum': 1.20, 'Hydrogen': 0.98, 'Iodine': 0.38, 'Quartz': 1.37,}
selling_levski = {'Agricium': 25.60, 'Altruciatoxine': 11.63, 'Beryl': 4.25, 'Chlorine': 1.56, 'Corundum': 2.53, 'Diamond': 6.07, 'Distilled Spirits': 4.95, 'Fluorine': 2.80, 'Gold': 6.07, 'Laranite': 28.25, 'Medical Supply': 18.00, 'Processed Food': 1.38, 'Scrap': 1.68, 'Stims': 3.40, 'Titanium': 8.27, 'Tungsten': 3.90, 'Widdow': 24.00,}
buying_grim_hex = {'Chlorine': 1.44, 'Flurine': 2.63, 'Hydrogen': 0.97, 'Iodine': 0.34}
selling_grim_hex = {'Altruciatoxine': 11.80, 'distilled spirits': 4.95, 'medical suppies': 18.05, 'processed food': 1.36, 'stims': 3.40, 'Widdow': 24.0}


#### Sorting the dict into ascending value instead of alphabetical
sort_buying_olisar = sorted(buying_olisar, key=lambda tup: tup[1])
sort_selling_olisar = sorted(selling_olisar, key=lambda tup:(tup[1], tup[0]))
sort_buying_levski = sorted(buying_levski, key=lambda tup: tup[1])
sort_selling_levski = sorted(selling_levski, key=lambda tup:(tup[1], tup[0]))
sort_buying_grim_hex = sorted(buying_arc_corp_mining_area_157, key=lambda tup: tup[1])
sort_selling_grim_hex = sorted(selling_arc_corp_mining_area_157, key=lambda tup:(tup[1], tup[0]))

#### picking two dicts (buy/sell) and filtering them to print only common elements.
def common(curr, other):
    return set(curr.keys()).intersection(set(other.keys()))
tradable_items = common(buying_levski, selling_olisar)

#### calculating the prices between possible sales.
prices = {k: selling_olisar[k] - buying_levski[k] for k in tradable_items}

#### finding the most profitable material
import operator
most_profitable_resourse = max(prices.items(), key=operator.itemgetter(1))[0]

#### sorting and printing the most profitable purchase.
profit_ammount = prices
profit_sorted = (f'{profit_ammount[most_profitable_resourse]:.2f}')
print(
f"The most profitable item to buy at {user_purchase_location.title()} is {most_profitable_resourse.title()}\n\
and will make a net profit of {profit_sorted} per unit when sold at {user_sale_destination.title()}"

What i am trying to do now is alter these two lines to reflect any input from the user opposed to just focusing on the two. This is why i added in the third area "grim_hex"

tradable_items = common(buying_levski, selling_olisar)
prices = {k: selling_olisar[k] - buying_levski[k] for k in tradable_items}

i have tried to create a second variable as follows:

user_purchase_location_1 = 'buying_'+user_purchase_location+''
user_sale_destination_1 = 'selling_'+user_sale_destination+''

these produce the correct information but wont work when added into the code as below as they are interpreted as strings:

def common(curr, other):
    return set(curr.keys()).intersection(set(other.keys()))
tradable_items = common(user_purchase_location_1, user_sale_destination_1)

prices = {k: user_sale_destination_1[k] - user_purchase_location_1[k] for k in tradable_items}

When im running it like that i get this error:

Traceback (most recent call last):
File "/home/floppypoppy/PycharmProjects/Star Citizen Trading Program/Star Citizen trading NEW.py", line 33, in <module>
tradable_items = common(user_purchase_location_1, user_sale_destination_1)
File "/home/floppypoppy/PycharmProjects/Star Citizen Trading Program/Star Citizen trading NEW.py", line 32, in common
return set(curr.keys()).intersection(set(other.keys()))
AttributeError: 'str' object has no attribute 'keys'

Sorry for the wall of text just trying to offer up as much information on what i am doing as possible. Is there anything you can suggest i research to to make the above work?

Again thanks for any help and kindest regards,

Harry (FP)