I'm finding my footing in data science and I came across an issue, I am creating a function that performs some computation for a hypothetical mobile subscription company

I created a dictionary as seen below:

mobile_sub = {'minutes_used': 200,
              'minutes_included': 200,
              'texts_used': 200,
              'texts_included': 200,
              'monthly_plan': 10,
              'cost_per_minute': 0.03,
              'cost_per_sms': 0.001,
              'vat_tax': 0.14}

then the function for the computation :

def evaluateCharges(input_data=[]):
    minutes_used = input_data['minutes_used']
    texts_used = input_data['texts_used']
   
    # Performing different actions based on the conditions indicated in the question.
    if minutes_used > 200:
        aditional_minutes = minutes_used-minutes_included
        basecharge = monthly_plan   (aditional_minutes * 0.03)
        
    if texts_used > 200 :
        aditional_texts = texts_used - texts_included
        basecharge = monthly_plan   (aditional_texts * 0.001)
        
    VAT_TAX = basecharge * vat_tax
    basecharge  = VAT_TAX
    

    # We can choose to format our basecharg  2dp
    finalCharges =  round(basecharge, 2) 

    # We then create a string with 
    output_string = "Dear Customer, below are the charges on your account : \n Minutes Used: '    str(minutes_used)   '\n Texts Used: '   str(texts_used)   '\n Additional Minutes: '   str(aditional_minutes)   '\n Additional Texts: '   str(aditional_texts)   '\n Basecharge: $'   str(basecharge)   '\n Tax Applied: 14% \n Total Charges: $'    str(taxApplied)"

    # the returning our output string
    return print(output_string)

Then calling our function and passing our dictionary

evaluateCharges(input_data=[ 250, 185])

This is where I got the error :TypeError: list indices must be integers or slices, not str, how can I avoid it?

TypeError                                 Traceback (most recent call last)
<ipython-input-25-a618d565246b> in <module>()
     36 # Then calling our function and passing our dictionary
     37 
---> 38 evaluateCharges(input_data=[ 250, 185])

<ipython-input-25-a618d565246b> in evaluateCharges(input_data)
      7     based on the values received.
      8     '''
----> 9     minutes_used = input_data['minutes_used']
     10     texts_used = input_data['texts_used']
     11 

TypeError: list indices must be integers or slices, not str

CodePudding user response：

Input data is supposed to be a map, but you are passing in [250, 185]. Then, when you index it with minutes_used = input_data['minutes_used'], it's telling you that you can't index it with a string.

CodePudding user response：

You are passing a two element list to the evaluateCharges function which is why the error is occurring. In python, you access list indices with the syntax mylist[index] where index is an integer. Here, you are trying to pass the strings minutes_used and texts_used as indices to the list called input_data. I think you intend input_data to be a dictionary instead of a list. It looks like you can get the desired behavior from passing your dictionary in instead:

mobile_sub = {'minutes_used': 200, 'minutes_included': 200, 'texts_used': 200, 'texts_included' : 200, 'monthly_plan': 10, 'cost_per_minute': 0.03 , 'cost_per_sms': 0.001, 'vat_tax': 0.14 }
evaluateCharges(input_data=mobile_sub)

Following this, your default value for input_data should be a dictionary instead of a list.