In Python, a string is an array of characters, we can access these characters using index operator []. For example, we have a_string = "Hello World" a_string[0] prints the first character in string ('H').
We can also use index operator to make substrings, for example a_string[0:3] will make a substring with first, second, third and fourth character equal to "Hell".
Now to business
my_string = "This is MY string!"
print(my_string[0:7]) # Prints "This is "
print(my_string[0:7:5]) # Prints "T" then prints the sixth character since we start counting at 0 hence prints "Ti" (note that space is also a character).
Hope this helps.
