Conform long lines to fit PEP 8

Question

I have a question about styling in PEP 8 (or cutting the number of characters in each line to be smaller).

Consider that I have a book with a bunch of different attributes and I want to concatenate them into some String.

books = [book_1, book_2, book_3]
for b in books:
  print("Thank you for using our Library! You have decided to borrow %s on %s. Please remember to return the book in %d calendar days on %s" %    
  (book.title, book.start_date, book.lend_duration, book.return_date"))

How can I shorten this line to ensure its readability?

Any ideas will help. PEP 8 is just 1 idea.

Answer 1

You can move your string outside the loop, and then format it before printing, like this:

message = 'Thank you for using our Library! You have decided to borrow {0.title} \
           on {0.start_date}. Please remember to return the book in \
           {0.lend_duration} calendar days on {0.return_date}'

for i in books:
    print(message.format(i))

Answer 2

As it's not mentioned in any other answer, you can use parenenthesis without using + or \:

>>> ("hello"
     " world")
'hello world'

Combined with Burhan's answer that gives you:

message = ('Thank you for using our Library! You have decided to borrow'
           ' {0.title} on {0.start_date}. Please remember to return the'
           ' book in {0.lend_duration} calendar days on {0.return_date}')

for b in books:
    print(message.format(b))