Perform sentiment analysis by using the gcloud tool

This page shows you how to get started with the Cloud Natural Language API using the Google Cloud SDK.

To follow step-by-step guidance for this task directly in the Google Cloud console, click Guide me :

Before you begin

If you don't already have one, sign up for a new account .

Install the Google Cloud CLI.

If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity .

To initialize the gcloud CLI, run the following command:

gcloud  
init

Create or select a Google Cloud project .

Roles required to select or create a project

Select a project : Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
Create a project : To create a project, you need the Project Creator ( roles/resourcemanager.projectCreator ), which contains the resourcemanager.projects.create permission. Learn how to grant roles .

Create a Google Cloud project:
```
gcloud projects create PROJECT_ID 
```
Replace PROJECT_ID with a name for the Google Cloud project you are creating.
Select the Google Cloud project that you created:
```
gcloud config set project PROJECT_ID 
```
Replace PROJECT_ID with your Google Cloud project name.

Verify that billing is enabled for your Google Cloud project .

Enable the Cloud Natural Language API:

Roles required to enable APIs

To enable APIs, you need the Service Usage Admin IAM role ( roles/serviceusage.serviceUsageAdmin ), which contains the serviceusage.services.enable permission. Learn how to grant roles .

gcloud  
services  
 enable 
  
language.googleapis.com

Install the Google Cloud CLI.

If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity .

To initialize the gcloud CLI, run the following command:

gcloud  
init

Create or select a Google Cloud project .

Roles required to select or create a project

Select a project : Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
Create a project : To create a project, you need the Project Creator ( roles/resourcemanager.projectCreator ), which contains the resourcemanager.projects.create permission. Learn how to grant roles .

Create a Google Cloud project:
```
gcloud projects create PROJECT_ID 
```
Replace PROJECT_ID with a name for the Google Cloud project you are creating.
Select the Google Cloud project that you created:
```
gcloud config set project PROJECT_ID 
```
Replace PROJECT_ID with your Google Cloud project name.

Verify that billing is enabled for your Google Cloud project .

Enable the Cloud Natural Language API:

Roles required to enable APIs

To enable APIs, you need the Service Usage Admin IAM role ( roles/serviceusage.serviceUsageAdmin ), which contains the serviceusage.services.enable permission. Learn how to grant roles .

gcloud  
services  
 enable 
  
language.googleapis.com

Make an entity analysis request

gcloud

Use the gcloud command line tool to call the analyze-entities command and use the --content flag to specify the text to analyze.

 gcloud  
ml  
language  
analyze-entities  
--content = 
 "Michelangelo Caravaggio, Italian painter, is known for 'The Calling of Saint Matthew'."

Command-line

Use curl to make a POST request to the documents:analyzeEntities method and provide the appropriate request body as shown in the following example.

The example uses the gcloud auth application-default print-access-token command to obtain an access token for the service account that you created when you set up the project.

curl  
-X  
POST  
\  
-H  
 "Authorization: Bearer " 
 $( 
gcloud  
auth  
application-default  
print-access-token ) 
  
\  
-H  
 "Content-Type: application/json; charset=utf-8" 
  
\  
 "https://language.googleapis.com/v1/documents:analyzeEntities" 
  
\  
--data  
 "{ 
 'document':{ 
 'type':'PLAIN_TEXT', 
 'content':'Michelangelo Caravaggio, Italian painter, is known for 
 \'The Calling of Saint Matthew\'.' 
 }, 
 'encodingType':'UTF8' 
 }"

You should see a response similar to the following:

 { 
  
 "entities" 
 : 
  
 [ 
  
 { 
  
 "name" 
 : 
  
 "Michelangelo Caravaggio" 
 , 
  
 "type" 
 : 
  
 "PERSON" 
 , 
  
 "metadata" 
 : 
  
 { 
  
 "wikipedia_url" 
 : 
  
 "http://en.wikipedia.org/wiki/Caravaggio" 
 , 
  
 "mid" 
 : 
  
 "/m/020bg" 
  
 }, 
  
 "salience" 
 : 
  
 0.83047235 
 , 
  
 "mentions" 
 : 
  
 [ 
  
 { 
  
 "text" 
 : 
  
 { 
  
 "content" 
 : 
  
 "Michelangelo Caravaggio" 
 , 
  
 "beginOffset" 
 : 
  
 0 
  
 }, 
  
 "type" 
 : 
  
 "PROPER" 
  
 }, 
  
 { 
  
 "text" 
 : 
  
 { 
  
 "content" 
 : 
  
 "painter" 
 , 
  
 "beginOffset" 
 : 
  
 33 
  
 }, 
  
 "type" 
 : 
  
 "COMMON" 
  
 } 
  
 ] 
  
 }, 
  
 { 
  
 "name" 
 : 
  
 "Italian" 
 , 
  
 "type" 
 : 
  
 "LOCATION" 
 , 
  
 "metadata" 
 : 
  
 { 
  
 "mid" 
 : 
  
 "/m/03rjj" 
 , 
  
 "wikipedia_url" 
 : 
  
 "http://en.wikipedia.org/wiki/Italy" 
  
 }, 
  
 "salience" 
 : 
  
 0.13870546 
 , 
  
 "mentions" 
 : 
  
 [ 
  
 { 
  
 "text" 
 : 
  
 { 
  
 "content" 
 : 
  
 "Italian" 
 , 
  
 "beginOffset" 
 : 
  
 25 
  
 }, 
  
 "type" 
 : 
  
 "PROPER" 
  
 } 
  
 ] 
  
 }, 
  
 { 
  
 "name" 
 : 
  
 "The Calling of Saint Matthew" 
 , 
  
 "type" 
 : 
  
 "EVENT" 
 , 
  
 "metadata" 
 : 
  
 { 
  
 "mid" 
 : 
  
 "/m/085_p7" 
 , 
  
 "wikipedia_url" 
 : 
  
 "http://en.wikipedia.org/wiki/The_Calling_of_St_Matthew_(Caravaggio)" 
  
 }, 
  
 "salience" 
 : 
  
 0.030822212 
 , 
  
 "mentions" 
 : 
  
 [ 
  
 { 
  
 "text" 
 : 
  
 { 
  
 "content" 
 : 
  
 "The Calling of Saint Matthew" 
 , 
  
 "beginOffset" 
 : 
  
 69 
  
 }, 
  
 "type" 
 : 
  
 "PROPER" 
  
 } 
  
 ] 
  
 } 
  
 ], 
  
 "language" 
 : 
  
 "en" 
 }

Clean up

Delete a Google Cloud project:

gcloud projects delete PROJECT_ID

What's next

Get started with the Natural Language API in your language of choice by using a Cloud Natural Language Client Library .
Consult the Natural Language Basics for conceptual information on forming Natural Language API requests and handling responses.
Try the Sentiment Analysis Tutorial and browse the Sample Applications .