Custom command for the ranger file manager for simple creation of annotations for files

commands.py

from __future__ import (absolute_import, division, print_function)

# You can import any python module as needed.
import os

# You always need to import ranger.api.commands here to get the Command class:
from ranger.api.commands import Command


class annotate_file(Command):
    # The so-called doc-string of the class will be visible in the built-in
    # help that is accessible by typing "?c" inside ranger.
    """:annotate_file <note> .. <content>

    This command creates .note.txt file for the currently selected file
    """

    # The execute method is called when you run this command in ranger.
    def execute(self):
        # self.arg(1) is the first (space-separated) argument to the function.
        # This way you can write ":my_edit somefilename<ENTER>".
        if self.arg(1):
            # self.rest(1) contains self.arg(1) and everything that follows
            note = self.rest(1)
        else:
            # if the is no note content given then exit
            return

        # self.fm is a ranger.core.filemanager.FileManager object and gives
        # you access to internals of ranger.
        # self.fm.thisfile is a ranger.container.file.File object and is a
        # reference to the currently selected file.
        target_filename = self.fm.thisfile.path + ".note.txt"
        # This is a generic function to print text in ranger.
        self.fm.notify("Creating note file for " + target_filename)

        with open(target_filename, "w") as target_file:
            target_file.write(note)

        # Using bad=True in fm.notify allows you to print error messages:
        if not os.path.exists(target_filename):
            self.fm.notify("Creating note file has failed!", bad=True)
            return

        # This executes a function from ranger.core.acitons, a module with a
        # variety of subroutines that can help you construct commands.
        # Check out the source, or run "pydoc ranger.core.actions" for a list.
        #self.fm.edit_file(target_filename)

    # The tab method is called when you press tab, and should return a list of
    # suggestions that the user will tab through.
    # tabnum is 1 for <TAB> and -1 for <S-TAB> by default
    def tab(self, tabnum):
        # This is a generic tab-completion function that iterates through the
        # content of the current directory.
        return self._tab_directory_content()