Gmail Connector for Python

Read / search Gmail messages, download attachments, send mail and more using Gmail REST API.

In this article you will learn how to quickly and efficiently integrate Gmail data in Python. We will use high-performance Gmail Connector to easily connect to Gmail and then access the data inside Python.

Let's follow the steps below to see how we can accomplish that!

Download Documentation

Gmail Connector for Python is based on ZappySys API Driver which is part of ODBC PowerPack. It is a collection of high-performance ODBC drivers that enable you to integrate data in SQL Server, SSIS, a programming language, or any other ODBC-compatible application. ODBC PowerPack supports various file formats, sources and destinations, including REST/SOAP API, SFTP/FTP, storage services, and plain files, to mention a few.

Create ODBC Data Source (DSN) based on ZappySys API Driver

Step-by-step instructions

To get data from Gmail using Python we first need to create a DSN (Data Source) which will access data from Gmail. We will later be able to read data using Python. Perform these steps:

Download and install ODBC PowerPack.
Open ODBC Data Sources (x64):
Create a User data source (User DSN) based on ZappySys API Driver:

ZappySys API Driver
- Create and use User DSN if the client application is run under a User Account. This is an ideal option in design-time, when developing a solution, e.g. in Visual Studio 2019. Use it for both type of applications - 64-bit and 32-bit.
- Create and use System DSN if the client application is launched under a System Account, e.g. as a Windows Service. Usually, this is an ideal option to use in a production environment. Use ODBC Data Source Administrator (32-bit), instead of 64-bit version, if Windows Service is a 32-bit application.
When the Configuration window appears give your data source a name if you haven't done that already, then select "Gmail" from the list of Popular Connectors. If "Gmail" is not present in the list, then click "Search Online" and download it. Then set the path to the location where you downloaded it. Finally, click Continue >> to proceed with configuring the DSN:

GmailDSN

Gmail

Now it's time to configure the Connection Manager. Select Authentication Type, e.g. Token Authentication. Then select API Base URL (in most cases, the default one is the right one). More info is available in the Authentication section.

User Account

Gmail authentication

To make this work you will have to create a Google Cloud project. This project forms the basis for creating, enabling, and using all Google Cloud services, including managing APIs, enabling billing, adding and removing collaborators, and managing permissions.

Go to the Google Cloud Console
In the Google Cloud console, go to menu IAM & Admin, and then Create a Project.
Enter the name of the new project into the Project Name field and select the appropriate organization, then click Create.
The console navigates to the Dashboard page and your project is created within a few minutes.
In the Google Cloud console, go to menu More products, Google Workspace, and then Product Library.
Now we need to enable the Gmail API.
Search for Gmail API. Select it and then click ENABLE.
Select the Credentials tab on the left side of the screen.
Select the + CREATE CREDENTIALS link to reveal a drop down menu.
In the dropdown menu, select OAuth client ID.
If presented, click the CONFIGURE CONSENT SCREEN button and then elect the appropriate User Type based on your business needs. Otherwise, continue to step 16.
In the OAuth consent screen tab fill in your app's website and domain information, and then click SAVE AND CONTINUE.
In the Scopes section of the app registration, click ADD OR REMOVE SCOPES and add the following scopes:
- openid
- https://mail.google.com/
- https://www.googleapis.com/auth/userinfo.email
- https://www.googleapis.com/auth/userinfo.profile
- https://www.googleapis.com/auth/gmail.labels
- https://www.googleapis.com/auth/gmail.send
- https://www.googleapis.com/auth/gmail.modify
- https://www.googleapis.com/auth/gmail.compose
- https://www.googleapis.com/auth/gmail.readonly
After the scopes have been added, click SAVE AND CONTINUE.
Complete the wizard setting up scopes.
Select the Credentials tab on the left side of the screen.
Select the + CREATE CREDENTIALS link to reveal a drop down menu.
In the dropdown menu, select OAuth client ID.
In the Application type drop down, select Desktop application and then give your app client a name.
Select the CREATE button.
A popup window will appear that provides important information you should record for your records:
- Client ID
- Client secret
And then click OK.
Go to OAuth Consent Screen tab. Under Publishing Status click PUBLISH APP to ensure your refresh token doesnt expire often. If you planning to use App for Private use then do not have to worry about Verification Status after Publish.
Back to Connection UI, Enter the client ID and client secret into the required parameters.

API Connection Manager configuration

Just perform these simple steps to finish authentication configuration:

Set Authentication Type to User Account [OAuth]
Optional step. Modify API Base URL if needed (in most cases default will work).
Fill in all the required parameters and set optional parameters if needed.
Press Generate Token button to generate the tokens.
Finally, hit OK button:

GmailDSN

Gmail

User Account [OAuth]

https://gmail.googleapis.com/

Required Parameters
UseCustomApp	Fill-in the parameter...
Authorization URL	Fill-in the parameter...
Token URL	Fill-in the parameter...
Default API Version	Fill-in the parameter...
Default User Id	Fill-in the parameter...
Scope	Fill-in the parameter...
Optional Parameters
Client Id
Client Secret
RetryMode	RetryWhenStatusCodeMatch
RetryStatusCodeList	429
RetryCountMax	5
RetryMultiplyWaitTime	True
Redirect URL (Only for Web App)

Once the data source connection has been configured, it's time to configure the SQL query. Select the Preview tab and then click Query Builder button to configure the SQL query:

ZappySys API Driver - Gmail

Read / search Gmail messages, download attachments, send mail and more using Gmail REST API.

GmailDSN
Start by selecting the Table or Endpoint you are interested in and then configure the parameters. This will generate a query that we will use in Python to retrieve data from Gmail. Hit OK button to use this query in the next step.
```
SELECT * FROM Messages
```
Some parameters configured in this window will be passed to the Gmail API, e.g. filtering parameters. It means that filtering will be done on the server side (instead of the client side), enabling you to get only the meaningful data much faster.
Now hit Preview Data button to preview the data using the generated SQL query. If you are satisfied with the result, use this query in Python:
ZappySys API Driver - Gmail

Read / search Gmail messages, download attachments, send mail and more using Gmail REST API.

GmailDSN
```
SELECT * FROM Messages
```
You can also access data quickly from the tables dropdown by selecting <Select table>.

A WHERE clause, LIMIT keyword will be performed on the client side, meaning that the whole result set will be retrieved from the Gmail API first, and only then the filtering will be applied to the data. If possible, it is recommended to use parameters in Query Builder to filter the data on the server side (in Gmail servers).
Click OK to finish creating the data source.

Video Tutorial

Read data in Python

Using ODBC DSN

Use this code snippet to read the data using GmailDSN data source:

GmailDSN')
When you run the code it will make the API call and read the data:

Here is Python program's code in text format:


    import pyodbc
    conn = pyodbc.connect('DSN=GmailDSN')

    cursor = conn.cursor()

    #execute query to fetch data from API service
    cursor.execute("SELECT id,title FROM products")

    row = cursor.fetchone()
    while row:
        print(row)
        row = cursor.fetchone()

    ##For loop example
    #for row in cursor:
    #    print(row)

Using a full ODBC connection string

If you want to avoid being dependent on a DSN and creating multiple DSNs for each platform (x86, x64), then you can use a fully qualified connection string. Simply go to your DSN and copy the Connection String:

Open ODBC data source configuration and click Copy settings:

ZappySys API Driver - Configuration [Version: 2.0.1.10418]

ZappySys API Driver - Gmail

Read / search Gmail messages, download attachments, send mail and more using Gmail REST API.

GmailDSN
The window opens, telling us the connection string was successfully copied to the clipboard:

Then in your Python code use Connection String when initializing OdbcConnection object, for example:

conn = pyodbc.connect('DRIVER={ZappySys API Driver};ServiceUrl=https://yourservices.provider.com/api/xxxx....;AuthName=Http;')

How to install `pyodbc` in the Python?

You would need to install pyodbc in Python if you intend to establish connections to databases that support ODBC (Open Database Connectivity). This module facilitates communication between Python applications and various database management systems, enabling you to perform operations such as querying, retrieving data, and managing databases. Here's how you can install pyodbc in Python:

Installation Steps:

Ensure you have Python installed on your system. If not, download it from the official Python website and follow the installation instructions.
Open your terminal or command prompt.
Use the following command to install pyodbc using pip, the Python package installer:
```
python -m pip install "pyodbc"
```
Make sure you have a stable internet connection and the necessary permissions to install Python packages.

Reasons to Install:

If pyodbc is not installed, your Python script will generate the following error:
```
"ModuleNotFoundError: No module named 'pyodbc'"
```
.
Database Connectivity: pyodbc allows Python to connect to various databases that support ODBC, such as Microsoft SQL Server, PostgreSQL, MySQL, and more.
Data Operations: It facilitates the execution of SQL queries, retrieval of data, and other database operations from within Python scripts.
Cross-Platform Support: pyodbc is designed to work across different operating systems, including Windows, macOS, and various Linux distributions.
Simplicity and Efficiency: The module provides an intuitive interface for managing database transactions and connections, simplifying the process of working with databases in Python.

By installing pyodbc, you can seamlessly integrate your Python applications with a wide range of ODBC-supported databases, enabling efficient and effective data management and analysis.

Centralized data access via Data Gateway

In some situations, you may need to provide Gmail data access to multiple users or services. Configuring the data source on a Data Gateway creates a single, centralized connection point for this purpose.

This configuration provides two primary advantages:

Centralized data access
The data source is configured once on the gateway, eliminating the need to set it up individually on each user's machine or application. This significantly simplifies the management process.
Centralized access control
Since all connections route through the gateway, access can be governed or revoked from a single location for all users.

	Data Gateway	Local ODBC data source
Simple configuration
Installation	Single machine	Per machine
Connectivity	Local and remote	Local only
Connections limit	Limited by License	Unlimited
Central data access
Central access control
More flexible cost

If you need any of these requirements, you will have to create a data source in Data Gateway to connect to Gmail, and to create an ODBC data source to connect to Data Gateway in Python.

Let's not wait and get going!

Creating Gmail data source in Gateway

In this section we will create a data source for Gmail in Data Gateway. Let's follow these steps to accomplish that:

Search for gateway in Windows Start Menu and open ZappySys Data Gateway Configuration:
Go to Users tab and follow these steps to add a Data Gateway user:
- Click Add button
- In Login field enter username, e.g., john
- Then enter a Password
- Check Is Administrator checkbox
- Click OK to save
Now we are ready to add a data source:
- Click Add button
- Give Datasource a name (have it handy for later)
- Then select Native - ZappySys API Driver
- Finally, click OK
GmailDSN

ZappySys API Driver
When the ZappySys API Driver configuration window opens, configure the Data Source the same way you configured it in ODBC Data Sources (64-bit), in the beginning of this article.
Very important step. Now, after creating or modifying the data source make sure you:
- Click the Save button to persist your changes.
- Hit Yes, once asked if you want to restart the Data Gateway service.
This will ensure all changes are properly applied:

Skipping this step may result in the new settings not taking effect and, therefore you will not be able to connect to the data source.

Creating ODBC data source for Data Gateway

In this part we will create ODBC data source to connect to Data Gateway from Python. To achieve that, let's perform these steps:

Open ODBC Data Sources (x64):
Create a User data source (User DSN) based on ODBC Driver 17 for SQL Server:

ODBC Driver 17 for SQL Server

If you don't see ODBC Driver 17 for SQL Server driver in the list, choose a similar version driver.
Then set a Name of the data source (e.g. Gateway) and the address of the Data Gateway:

GatewayDSN

localhost,5000

Make sure you separate the hostname and port with a comma, e.g. localhost,5000.
Proceed with authentication part:
- Select SQL Server authentication
- In Login ID field enter the user name you used in Data Gateway, e.g., john
- Set Password to the one you configured in Data Gateway
Then set the default database property to GmailDSN (the one we used in Data Gateway):

GmailDSN
Continue by checking Trust server certificate option:
Once you do that, test the connection:
If connection is successful, everything is good:
Done!

We are ready to move to the final step. Let's do it!

Accessing data in Python via Data Gateway

Finally, we are ready to read data from Gmail in Python via Data Gateway. Follow these final steps:

Go back to Python.
Use this code snippet to read the data using GatewayDSN data source:

GatewayDSN')
Read the data the same way we discussed at the beginning of this article.
That's it!

Now you can connect to Gmail data in Python via the Data Gateway.

If you are asked for authentication details, use Database authentication or SQL Authentication option and enter credentials you used when configuring Data Gateway, e.g. john and your password.