CODEWITHSUNDEEP
pythonapiloopsdataframe
acertainKnight
acertainKnight

Reputation: 75

Change API call in for loop python

I am trying to call several api datasets within a for loop in order to change the call and then append those datasets together into a larger dataframe.

I have written this code which works to call the first dataset but then returns this error for the next call.

`url = base + "max=" + maxrec + "&" "type=" + item + "&" + "freq=" + freq + "&" + "px=" +px + "&" + "ps=" + str(ps) + "&" + "r="+ r + "&" + "p=" + p + "&" + "rg=" +rg + "&" + "cc=" + cc + "&" + "fmt=" + fmt

TypeError: must be str, not Response`

Here is my current code

import requests
import pandas as pd

base = "http://comtrade.un.org/api/get?"
maxrec = "50000"
item = "C"
freq = "A"
px="H0"
ps="all"
r="all"
p="0"
rg="2"
cc="AG2"
fmt="json"

comtrade = pd.DataFrame(columns=[])

for year in range(1991,2018):
    ps="{}".format(year)
    url = base + "max=" + maxrec + "&" "type=" + item + "&" + "freq=" + freq + "&" + "px=" +px + "&" + "ps=" + str(ps) + "&" + "r="+ r + "&" + "p=" + p + "&" + "rg=" +rg + "&" + "cc=" + cc + "&" + "fmt=" + fmt
    r = requests.get(url)
    x = r.json()
    new = pd.DataFrame(x["dataset"])
    comtrade = comtrade.append(new)

Upvotes: 1

Views: 475

Answers (2)

mafrasi2
mafrasi2

Reputation: 322

Disclaimer: the other answer is correct and you should use it.

However, your actual problem stems from the fact that you are overriding r here:

r = requests.get(url)
x = r.json()

During the next iteration r will still be that value and not the one you initialized it with in the first place. You could simply rename it to result to avoid that problem. Better let the requests library do the work though.

Upvotes: 0

chepner
chepner

Reputation: 530823

Let requests assemble the URL for you.

common_params = {
    "max": maxrec,
    "type": item,
    "freq": freq,
    # etc
}

for year in range(1991,2018):    
    response = requests.get(base, params=dict(common_params, ps=str(year))
    response_data = response.json()
    new = pd.DataFrame(response_data["dataset"])
    comtrade = comtrade.append(new)

Upvotes: 1

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