1 00:00:00,000 --> 00:00:04,990 Splitting and joining strings is a very common operation, especially in text 2 00:00:05,000 --> 00:00:08,990 based environments like the World Wide Web or when you are operating on a lot of text files. 3 00:00:09,000 --> 00:00:13,990 So Python provides some string methods for splitting and joining strings. 4 00:00:14,000 --> 00:00:14,990 Let's take a look at how that works. 5 00:00:15,000 --> 00:00:17,990 We'll take a string. We'll put it in a variable because we are going to be using 6 00:00:18,000 --> 00:00:19,990 it here quite a bit. 7 00:00:20,000 --> 00:00:25,990 And we'll say s = 'This is a string of words.' 8 00:00:26,000 --> 00:00:30,990 And if we want to split that string apart we can just say s.split. 9 00:00:31,000 --> 00:00:33,990 And it'll split the string apart on the white space. 10 00:00:34,000 --> 00:00:37,990 And in fact if there was a lot of white space in between the words, if 'tThis 11 00:00:38,000 --> 00:00:46,990 string was something like this is a string of words' like that .split. 12 00:00:47,000 --> 00:00:53,990 We see that it folds all the white space together first before splitting on the white space. 13 00:00:54,000 --> 00:00:56,990 So that's a very nice and handy thing to do. 14 00:00:57,000 --> 00:01:01,990 If we wanted to split on some other token besides the white space we can specify 15 00:01:02,000 --> 00:01:05,990 it in the split method but it won't do this folding thing. 16 00:01:06,000 --> 00:01:08,990 That folding thing is a special thing that it does just with the white space. 17 00:01:09,000 --> 00:01:11,990 And it only does that if you don't specify an argument to split it all. 18 00:01:12,000 --> 00:01:20,990 For example if I say s.split and I want to split it on say the i characters like that, 19 00:01:21,000 --> 00:01:24,990 then I'll get back a list of the string with all of the i's removed and the 20 00:01:25,000 --> 00:01:28,990 words separated on the i characters and you see the space is still in there. 21 00:01:29,000 --> 00:01:33,990 So let's go ahead and split it on the white space and assign it to a variable. 22 00:01:34,000 --> 00:01:38,990 We'll call the variable words = s.split like that. 23 00:01:39,000 --> 00:01:42,990 And now we have a list words is a list with a bunch of separate words in it. 24 00:01:43,000 --> 00:01:46,990 And it's utterable. I can say for w in words: 25 00:01:47,000 --> 00:01:50,990 print(w) and it'll print those words out separately. 26 00:01:51,000 --> 00:01:53,990 But I can also join them back together if I want to. 27 00:01:54,000 --> 00:01:59,990 I can say new string =, doing it with a colon in it, .join and so the join 28 00:02:00,000 --> 00:02:03,990 method operates on the token that's going to be used to join things back 29 00:02:04,000 --> 00:02:05,990 together not on the list of words. 30 00:02:06,000 --> 00:02:09,990 And so I say join and I say words like this. 31 00:02:10,000 --> 00:02:12,990 And now I have a new string, which is all of those words joined back 32 00:02:13,000 --> 00:02:13,990 together with colons. 33 00:02:14,000 --> 00:02:19,990 Or if I wanted to I could say put a string with a comma and a space in it 34 00:02:20,000 --> 00:02:21,990 and say .join(words). 35 00:02:22,000 --> 00:02:25,990 And I would get back a list of words with a comma and a space. 36 00:02:26,000 --> 00:02:28,990 So I can really put whatever I want to there in the string that I am going to 37 00:02:29,000 --> 00:02:29,990 use to join the words back together. 38 00:02:30,000 --> 00:02:34,990 So in a nutshell that's how we split and join strings in Python. 39 00:02:35,000 --> 00:02:36,990 Again this is a very common operation. 40 00:02:37,000 --> 00:02:40,990 This is something that you'll use quite a bit if you are working with any text files. 41 00:02:41,000 --> 00:02:42,990 If you are working on a World Wide Web, if you are working with mail, if you are 42 00:02:43,000 --> 00:02:44,990 doing any manipulation of text whatsoever. 43 00:02:45,000 --> 00:02:55,000 You are going to find a lot of uses for split and join.