如何将输入字符串附加到字典键int？

Question

I'm trying to make the following code prompt for an answer and than add that answer into the dictionary titled poll. I'm trying the append command which is usually used for list but it doesn't just work for a dictionary.

At the moment I neither managed to update the key values (my intended goal) or even managed to just add a new item to the dictionary (non intended).

poll = {
    'cat': 0,
    'dog': 0,
    'both': 0,
    'none': 0,
    }

prompt = "Are you a cat owner, dog owner, both, or none? "
prompt += "\nEnter 'quit' to stop this loop \n"
message = ""
while message != "quit":
    message = input(prompt)
    poll[message].append(value)
    if message != "quit":
        print("Your answer was submitted! \n")

print("Poll results:\n", poll)

Answer 1

If you want to add a new key-value pair to the dictionary, instead of appending you can do the following, although I do not see a variable value in your code. It will also update the value of existing key if entered again because dictionary cannot have duplicate keys

poll[message] = value

Assuming you take care of the variable value , the code will look like

As pointed out by David Buck, you need to move the poll[message] = value part inside the if statement

while message != "quit":
    message = input(prompt)
    if message != "quit":
        poll[message] = value
        print("Your answer was submitted! \n")

print("Poll results:\n", poll)

Answer 2

I think you may be mistaking something. You don't have any list nor a variable called value . If you are trying to count the number of people with pets you may use poll[message] += 1 .

Eg:

poll = {
    'cat': 0,
    'dog': 0,
    'both': 0,
    'none': 0,
    }

poll['cat'] += 1     # poll['cat'] = poll['cat'] + 1
poll['cat'] += 1     # poll['cat'] = poll['cat'] + 1
poll['dog'] += 1     # poll['dog'] = poll['dog'] + 1

print(poll)
# {'cat': 2, 'dog': 1, 'both': 0, 'none': 0}

In addition, you should change the condition of the while and the order of the if statement:

poll = {
    'cat': 0,
    'dog': 0,
    'both': 0,
    'none': 0,
    }

prompt = "Are you a cat owner, dog owner, both, or none? "
prompt += "\nEnter 'quit' to stop this loop \n"
message = ""
while True:
    message = input(prompt)
    if message != "quit":
        print("Your answer was submitted! \n")
    else:
        break
    poll[message] += 1


print("Poll results:\n", poll)

Test:

Are you a cat owner, dog owner, both, or none? 
Enter 'quit' to stop this loop 
>>> cat
Your answer was submitted! 

Are you a cat owner, dog owner, both, or none? 
Enter 'quit' to stop this loop 
>>> cat
Your answer was submitted! 

Are you a cat owner, dog owner, both, or none? 
Enter 'quit' to stop this loop 
>>> dog
Your answer was submitted! 

Are you a cat owner, dog owner, both, or none? 
Enter 'quit' to stop this loop 
>>> quit
Poll results:
 {'cat': 2, 'dog': 1, 'both': 0, 'none': 0}

Obviously, there are a lot more things you can do, like using poll.get(key, default) to add values, e.: poll[message] = poll.get(message, 0) + 1 , so even if the key doesn't exist in the dictionary it doesn't crash the script, instead, it makes a new key. Or before adding the value to the dictionary check if message in poll.keys(): poll[message] += 1 so the script only accepts cat , dog , both or none but not car or bird .

Answer 3

I would just update the value of the dictionary based on the vote. Here's an example for me entering 'dog':

Initial Dictionary:

poll = {
    'cat': 0,
    'dog': 0,
    'both': 0,
    'none': 0,
    }

My response:

my_response = 'dog'

Update the 'dog' key:

poll[my_response] += 1

Output:

{'cat': 0, 'dog': 1, 'both': 0, 'none': 0}

Answer 4

this need to work:

poll = {
    'cat': 0,
    'dog': 0,
    'both': 0,
    'none': 0,
    }

prompt = "Are you a cat owner, dog owner, both, or none? "
prompt += "\nEnter 'quit' to stop this loop \n"
message = ""
while message != "quit":
    message = input(prompt)
    if message in list(poll):
        pass
    else:
        #else it will give a error that it isn't a key
        continue
    num = poll[message]
    num += 1
    poll[message] = num
    if message != "quit":
        print("Your answer was submitted! \n")

print("Poll results:\n", poll)