Dec 14, 2010 · When you concatenate strings using the + operator, Python will call the __add__ method on the string on the left side passing the right side string as a parameter. – Addie Commented Dec 5, 2015 at 20:10

Sep 24, 2016 · One final thing to mention about strings is that using join() is not always best. In the instances where you are creating a new string from a pre-determined number of strings, using the addition operator is actually faster, but in cases like above or in cases where you are adding to an existing string, using join() should be your preferred method.

The speed can be contrasted with the fastest method for Python 2, which is + concatenation on my computer; and that takes 0.203 µs with 8-bit strings, and 0.259 µs if the strings are all Unicode.

Nov 23, 2011 · Well, you coud add strings to the list inside your loop, and after it, join them. It's much more efficient (in fact, it's the recommended way) than appending the strings inside the loop – Óscar López

See Format String Syntax for a description of the various formatting options that can be specified in format strings. This method of string formatting is the new standard in Python 3.0, and should be preferred to the % formatting described in String Formatting Operations in new code. New in …

If you are using python 3.6 and newer then you can use f-strings to do the task like this. print(f"I have {card.price}") just include f in front of your string and add the variable inside curly braces { }. Refer to a blog The new f-strings in Python 3.6: written by Christoph Zwerschke which includes execution times of the various method.

I'm new to Python and can't find a way to insert a string into a list without it getting split into individual characters: >>> list=['hello','world'] >>> list ['hello', 'world'] ...

f-strings. This is the recommended approach when possible. It looks like f'hanning{num}.pdf'. The names of variables to insert appear directly in the string. It is important to note that there is not actually such a thing as an "f-string"; it's not a separate type. Instead, Python will translate the code ahead of time: >>> def example(num): ...

Apr 8, 2012 · Strings are immutable so you can't insert characters into an existing string. You have to create a new string. You can use string concatenation to do what you want: yourstring = "L" + yourstring + "LL" Note that you can also create a string with n Ls by using multiplication: m = 1 n = 2 yourstring = ("L" * m) + yourstring + ("L" * n)

Sep 17, 2012 · @Wouter, it will not. On the one hand, only lists of strings can be joined; so list.join would be inappropriate for an arbitrary list. On the other, the argument of str.join can be any "iterable" sequence of strings, not just a list.