Using .format() in a dictionary with an API call

January 13, 2022

I am making an api call and in doing so I have to manually change the endDate in the payload every day. I can not use .format() inside a dictionary. Can anyone help out?

Current payload: where I am changing the endDate manually

payload = "{\"dimensions\":[\"AdsetId\",\"Adset\",\"CampaignId\",\"Campaign\",\"Device\",\"Day\",\"Month\",\"Year\",\"Week\",\"Os\"],\"metrics\":[\"AdvertiserCost\",\"Displays\",\"ClickThroughRate\",\"Cpc\",\"AppInstalls\",\"Clicks\"],\"timezone\":\"UTC\",\"advertiserIds\":\"69957\",\"currency\":\"USD\",\"startDate\":\"2022-01-01T00:00:00.0000000+00:00\",\"***endDate\":\"2022-01-13***T00:00:00.0000000+00:00\",\"format\":\"csv\"}"

Expected payload:

payload = "{\"dimensions\":[\"AdsetId\",\"Adset\",\"CampaignId\",\"Campaign\",\"Device\",\"Day\",\"Month\",\"Year\",\"Week\",\"Os\"],\"metrics\":[\"AdvertiserCost\",\"Displays\",\"ClickThroughRate\",\"Cpc\",\"AppInstalls\",\"Clicks\"],\"timezone\":\"UTC\",\"advertiserIds\":\"69957\",\"currency\":\"USD\",\"startDate\":\"2022-01-01T00:00:00.0000000+00:00\",\endDate\":\"{}T00:00:00.0000000+00:00\",\"format\":\"csv\"}".format(today)

Here today will be a variable with today’s date

>Solution :

That’s a string, not a dictionary and the .format thing that you want, works. Guessing that this is in fact JSON data, the normal way to do this sort of thing is to build a python dict and serialize it later. Using a python "f-string" makes it simple to call a function in the string format specification itself. datetime.datetime.utcnow() gives the current UTC time. It can be converted to a date and its isoformat method writes the format you want. So,

import datetime as dt
import json

data = {
    "dimensions": ["AdsetId", "Adset", "CampaignId", "Campaign",
        "Device", "Day", "Month", "Year", "Week", "Os"],
    "metrics": ["AdvertiserCost", "Displays", "ClickThroughRate", 
        "Cpc", "AppInstalls", "Clicks"],
    "timezone": "UTC", 
    "advertiserIds": "69957", 
    "currency": "USD", 
    "startDate": "2022-01-01T00:00:00.0000000+00:00", 
    "endDate": f"{dt.datetime.utcnow.date.isoformat()}T00:00:00.0000000+00:00", 
    "format": "csv"}
    
    
payload = json.dumps(data)
print(payload)