First commit of Main.py, that implements the CLI.

Main.py

+#!/usr/bin/env python
+""" Entry file for the Python todo.txt CLI. """
+
+import re
+import sys
+
+import Config
+import TodoFile
+import TodoList
+
+def print_iterable(p_iter):
+    """ Prints an iterable to the standard output, one item per line. """
+    for item in sorted(p_iter):
+        print item
+
+def usage():
+    """ Prints the usage of the todo.txt CLI """
+    pass
+
+def error(p_message):
+    """ Prints a message on the standard error. """
+    sys.stderr.write(p_message + '\n')
+
+class Application(object):
+    def __init__(self):
+        self.todolist = TodoList.TodoList([])
+        self.dirty = False
+
+    def add(self):
+        """ Adds a todo item to the list. """
+        if sys.argv[2]:
+            self.todolist.add(sys.argv[2])
+            self.dirty = True
+
+    def append(self):
+        """ Appends a text to a todo item. """
+
+        number = sys.argv[2]
+        text = sys.argv[3]
+
+        if number and text:
+            try:
+                number = int(number)
+                self.todolist.append(number, text)
+                self.dirty = True
+            except ValueError:
+                error("Invalid todo number given.")
+
+    def do(self):
+        number = sys.argv[2]
+
+        try:
+            number = int(number)
+            self.todolist.set_completed(number)
+            self.dirty = True
+        except ValueError:
+            error("Invalid todo number given.")
+
+    def pri(self):
+        number = sys.argv[2]
+        priority = sys.argv[3]
+
+        if number and priority:
+            if re.match('^[A-Z]$', priority):
+                try:
+                    number = int(number)
+                    self.todolist.todo(number).set_priority(priority)
+                    self.dirty = True
+                except AttributeError:
+                    error("Invalid todo number given.")
+                except ValueError:
+                    error("Invalid todo number given.")
+            else:
+                error("Invalid priority given.")
+
+    def list(self):
+        print self.todolist
+        # TODO: sort + filter
+
+    def run(self):
+        """ Main entry function. """
+        todofile = TodoFile.TodoFile(Config.FILENAME)
+
+        try:
+            self.todolist = TodoList.TodoList(todofile.read())
+        except Exception:
+            pass # TODO
+
+        subcommand = Config.DEFAULT_ACTION
+        if len(sys.argv):
+            subcommand = sys.argv[1]
+
+        if subcommand == 'add':
+            self.add()
+        elif subcommand == 'app' or subcommand == 'append':
+            self.append()
+        elif subcommand == 'do':
+            self.do()
+        elif subcommand == 'ls':
+            self.list()
+        elif subcommand == 'lsprj' or subcommand == 'listproj':
+            print_iterable(self.todolist.projects())
+        elif subcommand == 'lscon' or subcommand == 'listcon':
+            print_iterable(self.todolist.contexts())
+        elif subcommand == 'pri':
+            self.pri()
+        else:
+            usage()
+
+        if self.dirty:
+            todofile.write(str(self.todolist))
+
+if __name__ == '__main__':
+    Application().run()