a simple command line todo which reads and write to a text file

todo.py

#!/usr/bin/python
"""A simple command line todo for simplenoteapp synced via dropbox."""

import os, sys, datetime

class TaskList(object):
    def __init__(self, todo, done):
        self.todo = todo
        self.done = done

    def _display_file(self, fp):
        line = fp.readline()
        # not really having first line dedicated to file.
        # if not line == "%s\n" %filename: return "invalid %s file" %filename
        taskno = 1
        while line:
            if line: print "%02d  %s" %(taskno, line.strip())
            taskno = taskno + 1
            line = fp.readline()

    def list_tasks(self, text): 
        tasks = open(self.todo)
        return self._display_file(tasks)

    def add_task(self, text):
        with open(self.todo, "a+") as myfile: myfile.write("-  %s\n" %(text))

    def edit_task(self, text):
        lineno_raw, new_task = text.split(" ", 1)
        lineno = int(lineno_raw)
        fro = open(self.todo, "rb")
        current_line = 0
        while current_line < lineno:
            fro.readline()
            current_line += 1

        seekpoint = fro.tell()
        frw = open(self.todo, "r+b")
        frw.seek(seekpoint, 0)
        frw.writelines("-  %s" %new_task)
        frw.close()

    def mark_done(self, text):
        lineno = int(text)
        fro = open(self.todo, "rb")
        current_line = 0
        while current_line < lineno:
            fro.readline()
            current_line += 1

        seekpoint = fro.tell()
        frw = open(self.todo, "r+b")
        frw.seek(seekpoint, 0)

        # read the line we want to discard
        done_task = fro.readline().strip()
        # now move the rest of the lines in the file 
        # one line back 
        chars = fro.readline()
        while chars:
            frw.writelines(chars)
            chars = fro.readline()

        fro.close()
        frw.truncate()
        frw.close()
        with open(self.done, "a") as myfile:
            myfile.write("X %s %s" %(datetime.datetime.now().strftime('%Y-%m-%dT%H:%M:%S'), done_task))
        print "DONE"

    def show_done(self, text):
        tasks = open(self.done)
        return self._display_file(tasks)

    def remove_task(self, text):
        raw_data_array = text.split(" ", 1)
        if len(raw_data_array) == 1: raw_data_array = raw_data_array+["todo"]
        lineno_raw, new_file = raw_data_array
        lineno = int(lineno_raw)
        if new_file == "done": ofile = self.done
        else: ofile = self.todo
        fro = open(ofile, "rb")
        current_line = 0
        while current_line < lineno:
            fro.readline()
            current_line += 1

        seekpoint = fro.tell()
        frw = open(ofile, "r+b")
        frw.seek(seekpoint, 0)
        # read the line we want to discard
        done_task = fro.readline().strip()
        # now move the rest of the lines in the file 
        # one line back 
        chars = fro.readline()
        while chars:
            frw.writelines(chars)
            chars = fro.readline()

        fro.close()
        frw.truncate()
        frw.close()

    def not_found(self, text):
        print "invalid option"

def get_action(action_abbr, tasklist):
    action_directory = {"l": tasklist.list_tasks,
                        "a": tasklist.add_task,
                        "e": tasklist.edit_task,
                        "d": tasklist.mark_done,
                        "da": tasklist.show_done,
                        "r": tasklist.remove_task}
    return action_directory.get(action_abbr, tasklist.not_found)

def main():
    args = sys.argv
    if len(args) == 1: args = args+["l"]
    text = ' '.join(args[2:]).strip()
    tasklist = TaskList("/Users/yashh/Dropbox/notes/todo.txt",
                        "/users/yashh/Dropbox/notes/done.txt")
    action_abbr = args[1]
    return get_action(action_abbr, tasklist)(text)

if __name__ == '__main__': main()