13. Strings

Strings

In the video above, at the 1:32 mark, the str is written as follows salesman = '"I think you\'re an encyclopedia salesman'" , but the closing string literals should be double quotes " followed by single quotes ' .

Strings

Strings in Python are shown as the variable type str . You can define a string with either double quotes " or single quotes ' . If the string you are creating actually has one of these two values in it, then you need to be careful to assure your code doesn't give an error.

>>> my_string = 'this is a string!'
>>> my_string2 = "this is also a string!!!"

You can also include a \ in your string to be able to include one of these quotes:

>>> this_string = 'Simon\'s skateboard is in the garage.'
>>> print(this_string)
Simon's skateboard is in the garage.

If we don't use this, notice we get the following error:

>>> this_string = 'Simon's skateboard is in the garage.'
  File "<ipython-input-20-e80562c2a290>", line 1
    this_string = 'Simon's skateboard is in the garage.'
                         ^
SyntaxError: invalid syntax

The color highlighting is also an indication of the error you have in your string in this second case. There are a number of other operations you can use with strings as well. In this video you saw a few:

>>> first_word = 'Hello'
>>> second_word = 'There'
>>> print(first_word + second_word)

HelloThere

>>> print(first_word + ' ' + second_word)

Hello There

>>> print(first_word * 5)

HelloHelloHelloHelloHello

>>> print(len(first_word))

5

Unlike the other data types you have seen so far, you can also index into strings, but you will see more on this soon! For now, here is a small example. Notice Python uses 0 indexing - we will discuss this later in this lesson in detail.

>>> first_word[0]

H

>>> first_word[1]

e

The len() function

len() is a built-in Python function that returns the length of an object, like a string. The length of a string is the number of characters in the string. This will always be an integer.

There is an example above, but here's another one:

print(len("ababa") / len("ab"))
2.5

You know what the data types are for len("ababa") and len("ab"). Notice the data type of their resulting quotient here.