Taking characters out by number

01 / 07

Strings come out by number as well

A list handed you one item at a time with fruits[0].

As it turns out, a string takes exactly the same writing. Write name[0] and you get the first character.

name = "Noah"print(name[0])

Result

02 / 07

As with lists, the numbers start at 0. The first character is 0, the second is 1.

letter	N	o	a	h
index	0	1	2	3

"The first one is zero" throws everybody the first time. You have been down this road once with lists, so treat it as the same idea, used again.

name = "Noah"print(name[1])print(name[3])

Result

o
h

03 / 07

The minus numbers you could use on a list still work. [-1] is the last character, [-2] the one before it.

You get the last character without counting the length first, which is very useful indeed.

name = "Noah"print(name[-1])print(name[-2])

Result

h
a

04 / 07

len, which counted the items in a list, gives you the number of characters when you hand it a string.

Everything in there counts as one: letters, digits, spaces, punctuation. To len they are all simply one more thing in the row.

name = "Noah"print(len(name))

Result

05 / 07

A four-character string has no [4]. The numbers run from 0 to 3, and that is the lot.

Point at one that does not exist and Python stops with an error.

name = "Noah"print(name[4])

Result

IndexError: string index out of range

06 / 07

The single character name[0] gives you is a string in its own right. So you can join it with + or repeat it with *.

Out of a string comes a string. Same reasoning as a list handing you back one of its items.

name = "Noah"print(name[0] + name[-1])

Result

Nh

07 / 07

Put range and len together and you make the numbers from 0 upwards, which takes the characters out one by one.

That is the moment looping and indexing meet. Next lesson takes several characters at once rather than one.

name = "Amy"for i in range(len(name)):    print(name[i])

Result

A
m
y