<p>您可以使用一个简单的文本文件来存储待办事项并从中检索它们:</p>
<pre><code>import sys
fn = "todo.txt"
def fileExists():
"""https://stackoverflow.com/questions/82831/how-do-i-check-whether-a-fi
answer: https://stackoverflow.com/a/82852/7505395
"""
import os
return os.path.isfile(fn)
def saveFile(todos):
"""Saves your file to disk. One line per todo"""
with open(fn,"w") as f: # will overwrite existent file
for t in todos:
f.write(t)
f.write("\n")
def loadFile():
"""Loads file from disk. yields each line."""
if not fileExists():
raise StopIteration
with open(fn,"r") as f:
for t in f.readlines():
yield t.strip()
def printTodos(todos):
"""Prints todos with numbers before them (1-based)"""
for i,t in enumerate(todos):
print(i + 1, t)
def addTodo(todos):
"""Adds a todo to your list"""
todos.append(input("New todo:"))
return todos
def deleteTodos(todos):
"""Prints the todos, allows removal by todo-number (as printed)."""
printTodos(todos)
i = input("Which number to delete?")
if i.isdigit() and 0 < int(i) <= len(todos): # 1 based
r = todos.pop(int(i) - 1)
print("Deleted: ", r)
else:
print("Invalid input")
return todos
def quit():
i = input("Quitting without saving [Yes] ?").lower()
if i == "yes":
exit(0) # this exits the while True: from menu()
def menu():
"""Main loop for program. Prints menu and calls subroutines based on user input."""
# sets up all available commands and the functions they call, used
# for printing commands and deciding what to do
commands = {"quit": quit, "save" : saveFile, "load" : loadFile,
"print" : printTodos,
"add": addTodo, "delete" : deleteTodos}
# holds the loaded/added todos
todos = []
inp = ""
while True:
print("Commands:", ', '.join(commands))
inp = input().lower().strip()
if inp not in commands:
print("Invalid command.")
continue
# some commands need params or return smth, they are handled below
if inp == "load":
try:
todos = [x for x in commands[inp]() if x] # create list, no ""
except StopIteration:
# file does not exist...
todos = []
elif inp in [ "save","print"]:
if todos:
commands[inp](todos) # call function and pass todos to it
else:
print("No todos to",inp) # print noting to do message
elif inp in ["add", "delete"]:
todos = commands[inp](todos) # functions with return values get
# todos passed and result overwrites
# it
else: # quit and print are handled here
commands[inp]()
def main():
menu()
if __name__ == "__main__":
sys.exit(int(main() or 0))
</code></pre>