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.