Comprehensive Guide to Blessed in Python for Terminal Interfaces and TUI Development

Introduction to Blessed

Blessed is a Python library that provides convenient features for creating terminal interfaces and Text-based User Interfaces (TUI). This guide introduces Blessed along with numerous useful APIs and their code snippets, making it easier for developers to create impressive terminal-based programs.

Getting Started

To begin using Blessed, you must first install it:

  import blessed
  term = blessed.Terminal()

Basic API Examples

Below are some fundamental API methods provided by Blessed:

• Getting Terminal Size

        print(term.width)
        print(term.height)
      

• Styling Text with Colors

        print(term.red('This is red text'))
        print(term.bold('This is bold text'))
      

• Handling Input

        with term.cbreak():
            val = term.inkey()
            print(f'You pressed: {val}')
      

• Moving the Cursor

        print(term.move_xy(10, 10) + 'This text is at position (10,10)')
      

• Clearing the Screen

        print(term.clear)
      

Advanced API Examples

• Formatted Text

        formatted_text = term.bright_black_on_white('Stylish Text')
        print(formatted_text)
      

• Scrollable Content

        print(term.clear)
        for y in range(term.height):
            print(term.move_xy(0, y) + f'Line {y}')
        term.inkey()
      

• Detecting Terminal Size Changes

        with term.fullscreen():
            print(term.center(term.on_black(term.white('Resizing...'))))
            term.inkey()
      

Example Application: Simple To-Do List

Below is an example of a simple terminal-based To-Do list application using Blessed:

  import blessed

  term = blessed.Terminal()

  to_do_list = []

  def display_list():
      print(term.clear)
      print(term.bold('My To-Do List:'))
      for index, item in enumerate(to_do_list, start=1):
          print(f'{index}. {item}')
      print(term.inverse('(Press "a" to add, "q" to quit.)'))

  def add_task():
      print(term.clear + term.move_xy(0, 0))
      print('Enter the new task:')
      task = input()
      to_do_list.append(task)

  with term.cbreak(), term.hidden_cursor():
      while True:
          display_list()
          val = term.inkey()
          if val == 'a':
              add_task()
          elif val == 'q':
              break

Conclusion

Blessed is a powerful and easy-to-use library for creating terminal applications and TUIs in Python. By following the examples and using the various API methods highlighted, you can design robust and user-friendly text-based interfaces with ease.

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