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Text Analytics API Part 2

8:42 with Carling Kirk

We'll add serialization logic and make our request to the Text Analytics API.

Parsing the Sentiment Score to a Double

If you're not located in the United States, you might need to call an overload of the double.TryParse method that allows you to pass in the "en-US" culture info in order to successfully parse the string value.

double score;
if (double.TryParse(sentiment.Score, NumberStyles.Any,
    CultureInfo.GetCultureInfo("en-US"), out score))
{
    newsResult.SentimentScore = score;
}

For more information about how to get and set your current culture in .NET, see the MSDN documentation page for the CultureInfo.CurrentCulture property.

https://msdn.microsoft.com/en-us/library/system.globalization.cultureinfo.currentculture(v=vs.110).aspx

Formatting Numbers

Standard Numeric Format Strings

Project Ideas

  • 0:00

    We need to serialize our request data into JSON and

  • 0:03

    then send it to the text analytics API URL.

  • 0:07

    I wanna to show you a quicker way to use JSON.net to serialize objects

  • 0:11

    using the JSON convert class.

  • 0:13

    You might have seen it earlier in the JSON.net documentation.

  • 0:17

    String request Json =

  • 0:20

    JsonConvert.SerializeObject and

  • 0:26

    will send it the sentimentRequest.

  • 0:34

    There's one small bug I found with our sentiment request class.

  • 0:38

    Let's go fix it before we build our request.

  • 0:41

    This JSON property needs to be documents.

  • 0:44

    Let's go check the JSON response in the docs to make sure it matches.

  • 0:49

    There it is, okay, let's get back to our method.

  • 0:56

    We need to convert our request based on into a byte array so

  • 0:59

    we can pass it to the upload data method.

  • 1:02

    Remember when we talked about encoding?

  • 1:04

    It's a good practice to use UTFA for sending data over the Web.

  • 1:08

    UTFA is the most compatible encoding.

  • 1:11

    Let's convert our string into a byte array using UTFA.

  • 1:16

    To do that, we can use the Encoding

  • 1:21

    class by RequestBytes =

  • 1:26

    Encoding utf8.GetBytes,

  • 1:31

    and we'll pass it.

  • 1:34

    Our requestJson.

  • 1:37

    Then we can send it to the URL in our upload data method.

  • 1:43

    But our URL is still the old one.

  • 1:46

    Let's delete that.

  • 1:48

    And we'll put a string placeholder and paste in request bytes.

  • 1:53

    We need to go grab the URL from the documentation and

  • 1:55

    paste it into the upload data method.

  • 2:01

    Here it is.

  • 2:02

    Copy and paste.

  • 2:08

    Now, we can use the json convert class to deserialize the response.

  • 2:13

    But we need a string for that.

  • 2:14

    Json convert only deals with strings.

  • 2:19

    String sentiments.

  • 2:21

    equals encoding dot UTF8 dot Get String.

  • 2:29

    And we'll pass it our response.

  • 2:31

    And now we can use the deserialize object method on Json convert.

  • 2:36

    Sentiment response equals Json convert dot deserialize

  • 2:45

    And our type parameter is sentiment response,

  • 2:51

    and then we need to pass it the string of sentiments.

  • 2:56

    All right looking good.

  • 2:58

    Now we need to do something with the sentiments from the news headlines.

  • 3:02

    We can add a property to the NewsResult class

  • 3:05

    to store the sentiment scores from our text analytics response.

  • 3:09

    Let's take a look at the response JSON again.

  • 3:14

    The score field has decimals, so which type do you think we should use?

  • 3:18

    How about a double?

  • 3:20

    It doesn't need to be super precise.

  • 3:25

    New search class and

  • 3:28

    NewsResult public double

  • 3:33

    SentimentScore get set.

  • 3:38

    Now let's go back up to main In our program class.

  • 3:44

    Let's see where we can call this method.

  • 3:46

    How about right after we call GetNewsForPlayer?

  • 3:51

    SentimentResponse sentimentResponse

  • 3:58

    = GetSentimentResponse And

  • 4:03

    we'll pass it our list of news results.

  • 4:07

    Then we can loop through the sentiment responses.

  • 4:11

    So for each var sentiment in

  • 4:15

    sentimentResponse.Sentiments Cause it's a list,

  • 4:25

    and then let's add another loop to find the correct news result and

  • 4:30

    update the score, foreach (var newsResult in newsResults).

  • 4:41

    Will add a check to see if the headline matches the ID of the sentiment and

  • 4:46

    then we'll add the score to the news result object.

  • 4:49

    So if the news result headline.

  • 4:55

    because if you remember we put the Sentiment.id equal to the headline.

  • 5:04

    Then we'll add the score to the news result object equals sentiment.score.

  • 5:14

    But we need to parse the string from sentiment into a double

  • 5:17

    We can use good old Double.TryParse.

  • 5:20

    We'll need a double to hold the value.

  • 5:23

    If Double.TryParse, and

  • 5:29

    in we'll pass it sentiment.Score, and out score.

  • 5:38

    And so if that's successful,

  • 5:41

    we'll assign newsresult.sentiment score equals score.

  • 5:49

    We can get rid of this line right here Okay, and since

  • 5:56

    we found a match we can break out of this loop to continue to the next news result.

  • 6:02

    Now, let's add the sentiment score to the text that we write to the console,

  • 6:07

    Sentiment Score and we'll pass it a 0.

  • 6:12

    Since it's at the beginning, and then we'll need to change all these that

  • 6:16

    follow, One more

  • 6:22

    in the list here.

  • 6:27

    So we've got 1, 2, 3, 4, and then we'll need to add the sentiment score On

  • 6:32

    the result object, result.SentimentScore,

  • 6:38

    and I like to double check the numbers, we go one, two, three, four.

  • 6:42

    One, two, three, four, great.

  • 6:47

    Let's run it and see what we get All right.

  • 6:53

    It looks like our sentiments are there,

  • 6:55

    but do you think we should format them a little better?

  • 6:59

    The scores are supposed to represent a percentage.

  • 7:02

    We can use a numeric format or in our string.

  • 7:04

    format method.

  • 7:05

    The letter P.

  • 7:06

    will format the numeric value into a percentage.

  • 7:10

    Stop debugging.

  • 7:13

    So a lot like our date formatter, right here we just do a :P.

  • 7:17

    Now let's see what we get.

  • 7:23

    All right, great.

  • 7:25

    It's a percentage.

  • 7:27

    You can find more ways to format numbers with the link in the notes.

  • 7:31

    It's a lot easier to read.

  • 7:34

    Let's see, this is two percent, missing the injured Marco Verratti and

  • 7:38

    Claudio [LAUGH] Struggled,

  • 7:43

    yeah, I guess that's a low sentiment.

  • 7:45

    Let's look at some other ones here, Looking for low ones

  • 7:54

    These are all pretty high, 9%.

  • 7:57

    Looks like somebody had hand surgery.

  • 8:02

    Suffered the injury.

  • 8:04

    Yeah, that's pretty low.

  • 8:05

    All right, great Fantastic job.

  • 8:11

    You learned a lot in this course.

  • 8:13

    We learned about file IO and how to read and write files to your computer.

  • 8:17

    Then we explored how to parse text data into dates and numbers.

  • 8:21

    We use Json.net for serialization and then send

  • 8:24

    it over the Web Now you can take what you've learned and build some projects.

  • 8:29

    Go find some JSON data that interests you and build an app around it or

  • 8:33

    better yet find an API and use it to grab data from the web.

  • 8:37

    I've put some project ideas for you in the notes.

  • 8:40

    Go forth and build things.

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