Entries tagged as perl
Thursday, December 14. 2017
Working around the Yahoo Finance API shutdown disaster
A roaring went through the tech-savvy finance community when Yahoo suddenly shut down its Finance API on Nov 1, 2017. Dozens of libraries and scripts that had parsed HTTP output from this API for years ceased to work. No longer could libraries such as Finance::Quote query prices of stocks, funds and currencies and hand these over to other applications such as GnuCash. By using Finance::Quote—I even wrote an extension module for it—I was affected as well, and finally I stumbled upon a solution: Version 1.41 recently introduced an Alpha Vantage module, and querying this source instead of Yahoo is straightforward.
Unfortunately, using Debian or Ubuntu one has to install this version from source, but it's not that hard to do. And for using Alpha Vantage, you have to register for an API key, but that's also no issue. One of the things that still don't work is currency conversion, as that module is still tied to Yahoo's interface. Alpha Vantage does provide currency conversion through its API, though. Looking at AlphaVantage.pm I recreated a simple Perl logic to perform currency conversion. Note that I haven't packed it into a real Finance::Quote module, it's just a simple Perl script that Works For Me™. For simplicity, I don't do any error handling. It relies on an environment variable that contains the API key. Here's how I did it:
use lib '/home/user/lib/perl';
#not needed#use Finance::Quote;
#debug#use Data::Dumper;
use JSON qw( decode_json );
use HTTP::Request::Common;
my $pair = $ARGV[0]; # e.g. "XAU:EUR" for gold price in Euro
@curr = split( /:/, $pair );
my $API_KEY = $ENV{'ALPHAVANTAGE_API_KEY'};
$url = "https://www.alphavantage.co/query"
. "?function=CURRENCY_EXCHANGE_RATE"
. "&from_currency=" . $curr[0]
. "&to_currency=" . $curr[1]
. "&apikey=" . $API_KEY;
$ua = LWP::UserAgent->new;
$reply = $ua->request(GET $url);
#debug#my $code = $reply->code;
#debug#my $desc = HTTP::Status::status_message($code);
my $body = $reply->content;
my $json_data = JSON::decode_json $body;
#debug#print Dumper(\$json_data);
my %fx = %{$json_data->{'Realtime Currency Exchange Rate'}};
my $last_refresh = $fx{'6. Last Refreshed'};
$last_refresh = substr($last_refresh, 0, 10); # remove time
my $isodate = substr($last_refresh, 0, 10);
my $rate = $fx{'5. Exchange Rate'};
print $isodate . ' ' . $rate . "\n";
Tuesday, February 28. 2012
How to add new quote sources to GnuCash
... or, actually, to Perl’s Finance::Quote, under Ubuntu 11.10:
- Clone one of the source modules in /usr/share/perl5/Finance/Quote (came with libfinance-quote-perl), say, Morningstar.pm, and place it under a new name into /usr/local/lib/perl/5.12.4/Finance/Quote, say, as Morningstar/AT.pm. (That’s what I did, I’ll probably make that module available.)
- Modify this module into a uniquely new entity, providing appropriate IDs, like morningstar_at.
- `perl -e ‘use Finance::Quote::Morningstar::AT’` should not display anything—especially no error.
- Copy /usr/share/perl5/Finance/Quote.pm to /usr/local/lib/perl/5.12.4/Finance and add Morningstar::AT to @modules.
- Execute `gnc-fq-dump | grep --color=auto morningstar`, you should see both morningstar and morningstar_at.
Your new quote source should now be available to GnuCash:
- Go to Tools → Security Editor → Add (or Edit) and enter the appropriate “Symbol/abbreviation” and “ISIN, CUSIP or other code”—note that the symbol is not the ISIN in the case of Morningstar.at, it’s the ID in the URL! Check Get Online Quotes, switch to Unknown and select morningstar_at.
- Go to Tools → Price Editor and click Get Quotes. After a few seconds you should see new entries with the current prices.
Thursday, April 17. 2008
CPAN can be a dog
If your amavisd-new suddenly doesn’t want to start anymore, reporting that some required Perl modules aren’t installed allegedly, then maybe the cause is something like
Took me 2 hours. I need that CPAN stuff apart from Debian at least for Geo::IPfree to map IPs to country names for my web statistics.
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