Trying to get data from a API

Question

I want to get a list that contains the exchange rate for USD.

This displays the data inside the API for reference.

def ge(url):
 response = urllib.request.urlopen(url)
 content_str = response.read()
 content = json.loads(content_str)
 return json.dumps(content)
print (ge(url))

And I'm having trouble with this part of the code where I can't get the exchange rate for USD. My other problem is that when I get rid of 'base in i', I get a error message saying the following, "string indices must be integers".

import json
import urllib.request
url = "https://api.exchangeratesapi.io/latest"
def get_response(url):
 response = urllib.request.urlopen(url)
 content_str = response.read()
 content = json.loads(content_str)
 outList = []
 for i in content:
 if('rates' in i and 'base' in i):
 innerList = []
 innerList.append(float(i["USD"]))
 outList.append(innerList)
 return json.dumps(outList)
print (get_response(url)) 

Expected: 1.1218

Actual result: I keep getting a empty bracket with nothing in it.

• knh190: It's impossible to know what is content without reading API doc because it depends on returned JSON, if you'd like to make the post helpful, post your sample data.
• John Gordon: Given that error message, at least one element in content must be a plain string, and you can't index a string with i["USD"].
• T Tse: content['base']['USD'] is what you want. You should brush up on the basics as you seem to have no idea what a string or a dictionary is.
• furas: use print(content, type(content) ) to see what you have. If it is list then you can check print( content[0], type(content[0]) ). If it is dictionary then you can check print( content.keys() ), etc.
• 101arrowz: @ShioT actually, it's content['rates']['USD']. The value for the key base is 'EUR'.

Answer 1

The urllib GET request is merely returning a dictionary. We see it contains three keys: base (whose value is 'EUR'), rates (whose value is a dictionary containing conversion rates to the other currencies), and date (whose value is the current date). You want to get the conversion rate of USD. We therefore access the rates key with content['rates']. This returns a dictionary with keys being currency names ('GBP', 'USD', etc.) whose values are the amount of that currency that is required to equal 1 of the base. To access the value of the USD entry, we do content['rates']['USD'], which returns the desired result of 1.1218 USD per euro. These are basic python concepts, so be sure to know them before moving on to more advanced projects.

Revised code:

def get_response(url):
 response = urllib.request.urlopen(url)
 content_str = response.read()
 content = json.loads(content_str)
 return content['rates']['USD']

Answer 2

Tips:You can addprint(content) after the line content=json.loads(content_str),and then you could see the type of content, it's a nested Dictionary. @101arrowZ's code works well. We don't need to check whether the keys rates and base are in the dictionary, for the 'check' part is contained in content['rates']['USD']. If they are in content, the value may be returned; otherwise, return none.

• swiftly: Ahh.. I see what you mean, I will try that. Thank you.
• Juliecodestack: You're welcome! I'm very glad to help. Your question was my first answer on stackoverflow. What I told you above was the process of how I got the answer of your question. I ran the code on my computer and it worked.