String formatting review

Before you start defining custom string representations for objects, make sure you are comfortable working with strings and formatting them. If you need a refresher, take a minute to look through the official Python tutorial on string formatting.

In this exercise, consider the following code

my_num = 5
my_str = "Hello"

f = ...
print(f)

where the definition for f is missing.

Here are a few possible variants for the definition of f:

1.

f = "my_num is {0}, and my_str is {1}.".format(my_num, my_str)
 

2.

f = "my_num is {}, and my_str is \"{}\".".format(my_num, my_str)

3.

f = "my_num is {n}, and my_str is '{s}'.".format(n=my_num, s=my_str)

4.

f = "my_num is {my_num}, and my_str is '{my_str}'.".format()