是否可以在文件中添加两行相同的文本，只是数值不同

Question

I have a code which writes to file when user select a product for example the user select banana from program it will write in file

You have purchased 2 bananas for price of 200

but what if the user purchase 3 bananas more from the program. Is it possible to make this 2 to 5 and from price from 200 to 500

You have purchased 5 bananas for price of 500

The command i am using for writing into file is

print('You have purchased',quantity,'Bananas for price of',price, file=test.txt)

Answer 1

You can build a template string like that:

   >>> template_string = "You have purchased %s bananas for price of %s"

And then, you can fill in the variable placeholders with values later:

   >>> line_one = template_string % (2, 200)
   >>> line_one
   "You have purchased 2 bananas for price of 200"
   >>> line_two = template_string % (5, 500)
   >>> line_two
   "You have purchased 5 bananas for price of 500"

Let's say you have 5 use cases, you should build the line 5 times for each case:

banana_price = 100
banana_transactions = [2, 3, 6, 7, 11]
template_string = "You have purchased %s bananas for price of %s"
with open('transactions.txt', 'w') as myfile:
   for transaction in banana_transactions:
      myfile.write(template_string % (transaction, 
                                      banana_price*transaction))