Master post - Eoddata.com web service blog series
Sat 25 March 2017 by Adrian TorrieThis post is part 1 of the "Using Python with Eoddata.com web service" series:
- Master post - Eoddata.com web service blog series
- Login() - Eoddata.com web service blog series
- ExchangeList() - Eoddata.com web service blog series
- CountryList() - Eoddata.com web service blog series
- SymbolList() - Eoddata.com web service blog series
- FundamentalList() - Eoddata.com web service blog series
Summary¶
- Master post for the blog series that holds all the links related to making web service calls to Eoddata.com. Overview of the web service can be found here
- Download the class definition file for an easy to use client, which is demonstrated below
- This post shows you how to create a secure credentials file to hold the username and password so you don't have to keep entering it, and will allow for automation later.
- A quick overview is given below of establishing a session using the
requestsmodule, and parsing the xml response usingxml.etree.cElementTree. Then a quick inspection of the objects created follows.
The following links were used to help get these things working.
Version Control¶
In [2]:
%run ../../code/version_check.py
Change Log¶
Date Created: 2017-03-25
Date of Change Change Notes
-------------- ----------------------------------------------------------------
2017-03-25 Initial draft
2017-04-02 Added "file saved: " output Setup¶
In [3]:
%run ../../code/eoddata.py
from getpass import getpass
import json
import os
import os.path
import requests as r
import stat
import xml.etree.cElementTree as etree
ws = 'http://ws.eoddata.com/data.asmx'
ns='http://ws.eoddata.com/Data'
session = r.Session()
In [4]:
username = getpass()
In [5]:
password = getpass()
Secure Credentials File¶
Create credentials file for later usage. The file will have permissions created so only the current user can access the file. The following SO post was followed.
The following directory will be created if it doesn't exist:
- Windows:
%USERPROFILE%/.eoddata - Linux:
~/.eoddata
In [6]:
# gather credentials
credentials = {'username': username, 'password': password}
# set filename variables
credentials_dir = os.path.join(os.path.expanduser("~"), '.eoddata')
credentials_file_name = 'credentials'
credentials_path = os.path.join(credentials_dir, credentials_file_name)
# set security variables
flags = os.O_WRONLY | os.O_CREAT | os.O_EXCL # Refer to "man 2 open".
mode = stat.S_IRUSR | stat.S_IWUSR # This is 0o600 in octal and 384 in decimal.
# create directory for file if not exists
if not os.path.exists(credentials_dir):
os.makedirs(credentials_dir)
# for security, remove file with potentially elevated mode
try:
os.remove(credentials_path)
except OSError:
pass
# open file descriptor
umask_original = os.umask(0)
try:
fdesc = os.open(credentials_path, flags, mode)
finally:
os.umask(umask_original)
# save credentials in secure file
with os.fdopen(fdesc, 'w') as f:
json.dump(credentials, f)
f.write("\n")
print("file saved: {}".format(credentials_path))
Inspect the XML returned¶
In [7]:
call = 'Login'
url = '/'.join((ws, call))
payload = {'Username': username, 'Password': password}
response = session.get(url, params=payload, stream=True)
if response.status_code == 200:
root = etree.parse(response.raw).getroot()
Data inspection (root)¶
In [8]:
dir(root)
Out[8]:
In [9]:
for child in root.getchildren():
print (child.tag, child.attribute)
In [10]:
for item in root.items():
print (item)
In [11]:
for key in root.keys():
print (key)
In [11]:
print (root.get('Message'))
print (root.get('Token'))
print (root.get('DataFormat'))
print (root.get('Header'))
print (root.get('Suffix'))
Get data (token)¶
In [12]:
token = root.get('Token')
Client¶
In [13]:
# client can be opened using a with statement
with (Client()) as eoddata:
print('token: {}'.format(eoddata.get_token()))
In [14]:
# initialise using secure credentials file
eoddata = Client()
# client field accessors
ws = eoddata.get_web_service()
ns = eoddata.get_namespace()
token = eoddata.get_token()
session = eoddata.get_session()
print('ws: {}'.format(ws))
print('ns: {}'.format(ns))
print('token: {}'.format(token))
print(session)
In [15]:
# the client has a list of exchange codes avaiable once intialised
eoddata.get_exchange_codes()
Out[15]:
In [16]:
# client must be closed if opened outside a with block
session.close()
eoddata.close_session()
