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The string object in Python supports a lot of standard methods.

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We're going to take a look at just some of them here.

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We'll start with a string. I'm going to go ahead and put it in a variable and

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say s = 'this is a string'.

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And notice that's all lowercase, and we just look at the string by itself.

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It looks like that.

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If I say capitalize(), then we get it with just the first letter capitalized.

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I want all the letters capitalized I can say .upper() and there is certainly a

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lot of use for that.

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Likewise, I can say .lower(). Of course it was all lowercase before, so I had

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'THIS IS A STRING' in all uppercase I can say .lower().

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And we'll see that we get the lowercase version of that.

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We can also say swapcase().

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So if I had 'This Is A String,' sort of title case-ish, I say .swapcase().

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Then I get it in the opposite case.

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If I take our string, which says, 'this is a string' and I want to find a

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particular word in it, I can look for it say the word "is."

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And we will find it at position 2.

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And you might look here and you might say, well, "is" is at position 0, 1, 2, 3,

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4, 5, but in fact, it found this.

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So it's looking for exactly that string.

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In the first occurrence of it is the one that get will return.

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And so the first letter is 0, the second letter is 1, and then "is" starts at position 2.

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We can also do string replace.

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I can say s.replace, this for that.

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And it'll say 'that is a string'.

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Now, it's important to note that the string itself is immutable.

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So the string has not changed with these functions do as they return a different string.

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And it's an entirely different string object that gets returned.

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For example, if I look at the id of (s) I'll see that its id is that number there.

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And if I say newstring = s.upper(), I now have a new string which is

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the uppercase string.

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It's that different string that was returned by the upper() method.

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If I look at the id of (newstring), you'll see that it's entirely different than the

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id of 'this is a string'.

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So there's few more useful ones, there is a strip. I say s.strip().

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What strip does is that strips a particular sequence of characters from both

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the end of the string and the beginning of the string.

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By default what it strips is whitespace.

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So if I have a string that says ' this is a string ' like that, with a bunch of

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whitespace at the beginning and the end of it,

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and I say .strip(),

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I'll get back the string without that whitespace at the beginning and the ending of that.

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And so where this very commonly used for is removing new lines, but you need to

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be aware when you use it for that, that it will also remove any leading space.

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If you want to just remove whitespace from the end of string, you can use rstrip().

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And that will remove the whitespace from the end of a string and not change

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anything at the beginning of the string.

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And if you just want to remove a new line, let's say we have a string, I'm going

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to put this in a variable because we need it a couple of times, and say s1 =

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'This is a string\n' with the newline at the end of it.

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I said sting instead of string. That will work.

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And there we see we have the string with a newline at the end of it.

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If I say s1.strip(), of course, it'll remove the new line.

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And that's very useful, but it will also remove any whitespace from the

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beginning or the end.

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If I just want to remove the new line from the end, I can actually say

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s1.rstrip and specify the newline.

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So whatever string you specify, parenthesis is what will be stripped.

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And there we have it with just a newline taken from just the end of the string.

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There's also a set of methods for testing the content of a string really quickly.

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We'll look at these. We can say s.isalnum().

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And what that is, is that it checks if the string has only

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alphanumeric characters in it.

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And of course, this is False because it also had spaces in it.

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If I have a string that looks like 'thisisastring' and has no spaces in it and I

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say .alnum() and it'll come up True.

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I must have spelled something wrong. I did. 'thisisastring'.isalnum() and

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that comes up True.

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So these methods that start with "is," there is a bunch of them. I'm just going to

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show you a few. There's isalpha(), 'thisisastring'.isalpha().

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And that checks just for alpha characters.

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So that would be the letters a-z or other alpha characters in other text

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encodings beside just ASCII.

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And there is also one for checking if it is digit.

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And so if I have a string that's just digits and say isdigit(), that one will

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come up True, but if I check s.isdigit() it will of course come up False.

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And finally there's isprintable(), which checks to see if all the characters in

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the string are printable.

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So those are some of most common and most popular methods that are available

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for the string class.