Python: TypeError: can't multiply sequence by non-int of type str

Question

So, I was making a text-based “shopping” program, and I came across an error that didn’t quite make sense to me. The error message was this:

TypeError: can't multiply sequence by non-int of type str

Here is a code snippet of where I think the error is located (Comment above line where I believe error to be located):

def buy():
    print "nType in a store item to buy."
    find_item = raw_input(prompt)
    if find_item in store_items:
        print "Amount?"
        amount = raw_input(prompt)
        if amount:
                        #Error in next line?
            store_rec.append(store_items[find_item] * amount)
            get_buy()

If you’re wondering, store_items is a dictionary containing the store items like this:

store_items = {
    "carrot": "carrot",
    "apple": "apple",
    "pear": "pear",
    "taco": "taco",
    "banana": "banana",
    "tomato": "tomato",
    "cranberry": "cranberry",
    "orange": "orange",
}

Then store_rec is an empty list, like this:

store_rec = []

It contains recommendations for telling the user what to buy next time, but that’s not where I think the error is located. What I was trying to do in the line where the error appears to be, is append the amount of items specified by the user to the empty store_rec list. Unfortunatly, then I get the error. It seems like it should work, but it doesn’t. So, with that in mind, any help on my problem is appreciated!

Asked By: NotAGoodCoder

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Source

Answer 1

If you read the error carefully, it’s telling you what’s wrong — it’s nonsensical to multiply a sequence by a string; the string must be converted to an integer first.

Convert the amount to an integer by changing the line:

amount = raw_input(prompt)

to

amount = int(raw_input(prompt))

Answered By: Mark Simpson

Python: TypeError: can't multiply sequence by non-int of type str

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