global_charts_dump.py

import datetime
import requests
import json

BASE_URL = 'http://charts.spotify.com/api/charts/most_streamed/global/%s'

first_date = datetime.date(2013,04,28)
data = {}

for i in xrange(50):
    req_date = datetime.datetime.strftime(first_date + datetime.timedelta(i*7), '%Y-%m-%d')
    try:
        data[req_date] = requests.get(BASE_URL % (req_date)).json()
    except:
        break

print json.dumps(data)

# to run, just pipe to a file (for example)
# python this_file.py | tee > output.json