CODEWITHSUNDEEP
jsonpython-3.xdjangodjango-rest-frameworkdecimal
Amit Yadav
Amit Yadav

Reputation: 59

How to pass a decimal value when making a post request in django?

I am trying to make a post request to a third party application along with some data and the data also have a decimal value up to two points, which I am getting from database (order.amount) but after making the request getting error saying data is not serializable to json then i passed it as '"%s"' % round(order.amount,2) then also getting error post data is empty.Looking for suggestion to solve this problem.

    request = Transfer.request_transfer(beneId=beneficiary_id, amount=round((order.amount),2) 
    transferId=transfer_identifier,remarks="Test transfer")

    getting error: decimal is not json serializable

    print('"%s"' % round((order.amount),2) #"5000.23"
    
    request = Transfer.request_transfer(beneId=beneficiary_id, amount='"%s"' % round((order.amount),2) transferId=transfer_identifier,remarks="Test transfer")
    
    getting error : PreconditionFailedError: Reason = Post data is empty or not a valid JSON:: response = {"status": "ERROR", "subCode": "412", "message": "Post data is empty or not a valid JSON"}
    
    
    but when hardcoding amount then it is working
    request = Transfer.request_transfer(beneId=beneficiary_id, amount= "5000.23" transferId=transfer_identifier,remarks="Test transfer")

Upvotes: 0

Views: 1140

Answers (2)

Fedor Ivanov
Fedor Ivanov

Reputation: 60

Pay attention to this line,

print('"%s"' % round((order.amount),2) #"5000.23"

I guess you miss one thing: you're formatting your decimal value, but you do this with quotes, so your variable amount will contain "5000.23" string instead of 5000.23.

So, look:

request = Transfer.request_transfer(beneId=beneficiary_id, amount='"%s"' % round((order.amount),2) transferId=transfer_identifier,remarks="Test transfer")

you have amount='"5000.23"' and these quotes get in the way of serialization.

To fix it, just remove the additional quotes:

print('%s' % round((order.amount),2) # '5000.23'

request = Transfer.request_transfer(beneId=beneficiary_id, amount='%s' % round((order.amount),2) transferId=transfer_identifier,remarks="Test transfer")

Upvotes: 1

Abdul Aziz Barkat
Abdul Aziz Barkat

Reputation: 21802

The round function according to Python docs:

The return value is an integer if ndigits is omitted or None. Otherwise the return value has the same type as number.

Hence round when passed a Decimal and ndigits will return a Decimal, hence passing amount=round((order.amount),2) will not do what you assume it does (converting to float or int). Also converting Decimal to float implies a loss of precision which we don't want (The whole reason we would be using Decimal). To pass a Decimal value one would simply pass it as a string (Which of course implies we would need to perform some type casting at the client side if we want to perform arithmetic using it):

request = Transfer.request_transfer(
    beneId=beneficiary_id,
    amount=str(order.amount),
    transferId=transfer_identifier,
    remarks="Test transfer"
)

Upvotes: 0

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