helper-scripts 0.4.3

Database Helper Package

HELPER SCRIPTS

Built for data professionals by data professionals.

Note: Despite the tagline, this package can be used by anyone.

PACKAGE DESCRIPTION

DatabaseHandler

This code defines a class called DatabaseHandler that provides methods for interacting with a PostgreSQL database.

1. It imports necessary modules: ConfigParser from configparser, psycopg2, DictCursor from psycopg2.extras, and sys.

2. The DatabaseHandler class is defined.

3. The __init__ method initializes the DatabaseHandler object with the config_file and config_file_section parameters. It also initializes self.conn as None.

4. The read_db_config method reads the configuration file specified in self.config_file using ConfigParser. It retrieves the parameters for the PostgreSQL section specified in self.config_file_section and returns them as a dictionary.

5. The connect method establishes a connection to the database using the parameters obtained from read_db_config.

6. The get_cursor method creates a cursor for executing database queries. It checks if a connection exists or is closed and connects if necessary. It returns a cursor with DictCursor as the cursor factory, which returns query results as dictionaries.

7. The close method closes the database connection if it is open.

8. The commit method commits the currently open transaction.

9. The rollback method rolls back the currently open transaction.

10. The execute method creates a cursor, executes a query with optional arguments, and returns the cursor. If an exception occurs during query execution, it rolls back the transaction, closes the cursor, and raises the exception.

11. The fetchone method executes a SELECT query that is expected to return a single row. It calls the execute method internally, fetches the first row from the cursor, closes the cursor, and returns the row as a psycopg2 DictRow.

12. The fetchall method executes a SELECT query that is expected to return multiple rows. It calls the execute method internally, fetches all rows from the cursor, closes the cursor, and returns the rows as a list of psycopg2 DictRow objects.

13. The copy_to method executes a COPY command to copy data from a table to a file. It opens the file specified in path and uses copy_to method of the cursor to perform the copying. If an exception occurs, it closes the cursor and raises the exception.

14. The sql_copy_to method executes an SQL COPY command to copy data from a table to a file. It opens the file specified in path and uses copy_expert method of the cursor to perform the copying. If an exception occurs, it closes the cursor and raises the exception.

15. The sql_copy_from method executes an SQL COPY command to copy data from a file to a table. It opens the file specified in path and uses copy_expert method of the cursor to perform the copying. If an exception occurs, it closes the cursor and raises the exception.

16. The copy_from method executes a COPY command to copy data from a file to a table. It opens the file specified in path and uses copy_from method of the cursor to perform the copying. If an exception occurs, it closes the cursor and raises the exception.

Overall, this code provides a set of methods to interact with a PostgreSQL database, including connecting to the database, executing queries, fetching results, and performing data copying operations using the psycopg2 library.

SendMail

This code defines a class called SendMail that is responsible for sending emails using the smtplib library. Here's a breakdown of what the code is doing:

1. It imports necessary modules: MIMEBase, smtplib, ssl, MIMEText, MIMEMultipart, encoders from email.mime and email, Helpers from database_handler, config from database_handler, and path from os.

2. It reads the email server configuration parameters from a configuration file using the CONFIG class from database_handler and assigns them to the params variable.

3. The SendMail class is defined.

4. The send_email method is defined within the SendMail class. It takes several parameters: email_message (the body of the email), subject (the subject of the email), email_recepients (a list of recipient email addresses), and file_attachments (a list of file paths for attachments, optional).

5. Inside the method, it retrieves the necessary email server configuration parameters from params.

6. It creates an instance of MIMEMultipart to construct the email message.

7. It sets the email subject, sender, recipient(s), and Cc fields of the message.

8. It constructs the HTML content of the email using the email_message parameter.

9. It attaches the HTML content to the email message using MIMEText and the 'html' subtype.

10. If there are file attachments, it iterates over the file_attachments list, opens each file, creates a MIMEBase object, reads the file content, encodes it using Base64, and adds it as an attachment to the email message.

11. It creates a SSL context using ssl.create_default_context().

12. It establishes a connection to the SMTP server specified in the email server configuration using smtplib.SMTP().

13. It starts a TLS connection with the server using server.starttls().

14. It authenticates with the server using the login email and password specified in the email server configuration.

15. It sends the email message using server.sendmail().

16. If an exception occurs during the process, it is raised.

Overall, this code provides a class that encapsulates the functionality to send emails with attachments using an email server specified in a configuration file.

GoogleDrive

This code defines a class worker that provides various functionalities to interact with Google Drive using the Google Drive API. Below is a description of the key components and functionalities of this code:

Class worker

Class Attributes

• scope_readonly: Scope for read-only access to Google Drive.
• scope_write: Scope for read and write access to Google Drive.
• initial_download_path: Default path for downloading files, set to the current working directory.

Constructor

• __init__(self, api_name='drive', api_version='v3', key_file_location=''): Initializes the class with API name, version, and the location of the key file.

Methods

1. construct_service(self, scope: str = None):

   • Constructs and returns a Google Drive service instance with the specified scope.

2. read_drive_files(self, scope=scope_readonly, file_id: str = None, filename: str = None, ignore_trashed=True):

   • Reads files from Google Drive based on file ID or filename, with an option to ignore trashed files.

3. download_drive_file(self, file_id=None, download_path=initial_download_path, filename=None, scope=scope_write):

   • Downloads a file from Google Drive based on file ID or filename to a specified download path.

4. upload_file_to_drive(self, scope=scope_write, filename=None, file_path=None, parent_folder_id=None, mimetype=None, coerce=True):

   • Uploads a file to Google Drive with the specified parameters.

5. get_file_permissions(self, file_id=None):

   • Retrieves and returns the permissions of a specified file on Google Drive.

6. delete_drive_files(self, file_ids: list = [], reset=False):

   • Deletes specified files from Google Drive. If reset is True, it deletes all files.

Error Handling

• The code handles errors using try-except blocks and returns appropriate error messages and codes.

Usage

• The class worker can be instantiated and used to interact with Google Drive, performing operations like reading, downloading, uploading, checking permissions, and deleting files.

This code provides a structured way to interact with Google Drive using the Google Drive API, encapsulating the logic within a class for ease of use and reusability.