- <title>Datalagringsdirektivet kaster skygger over Høyre og Arbeiderpartiet</title>
- <link>http://people.skolelinux.org/pere/blog/Datalagringsdirektivet_kaster_skygger_over_H_yre_og_Arbeiderpartiet.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Datalagringsdirektivet_kaster_skygger_over_H_yre_og_Arbeiderpartiet.html</guid>
- <pubDate>Thu, 7 Sep 2017 21:35:00 +0200</pubDate>
- <description><p>For noen dager siden publiserte Jon Wessel-Aas en bloggpost om
-«<a href="http://www.uhuru.biz/?p=1821">Konklusjonen om datalagring som
-EU-kommisjonen ikke ville at vi skulle få se</a>». Det er en
-interessant gjennomgang av EU-domstolens syn på snurpenotovervåkning
-av befolkningen, som er klar på at det er i strid med
-EU-lovgivingen.</p>
-
-<p>Valgkampen går for fullt i Norge, og om noen få dager er siste
-frist for å avgi stemme. En ting er sikkert, Høyre og Arbeiderpartiet
-får ikke min stemme
-<a href="http://people.skolelinux.org/pere/blog/Datalagringsdirektivet_gj_r_at_Oslo_H_yre_og_Arbeiderparti_ikke_f_r_min_stemme_i__r.html">denne
-gangen heller</a>. Jeg har ikke glemt at de tvang igjennom loven som
-skulle pålegge alle data- og teletjenesteleverandører å overvåke alle
-sine kunder. En lov som er vedtatt, og aldri opphevet igjen.</p>
-
-<p>Det er tydelig fra diskusjonen rundt grenseløs digital overvåkning
-(eller "Digital Grenseforsvar" som det kalles i Orvellisk nytale) at
-hverken Høyre og Arbeiderpartiet har noen prinsipielle sperrer mot å
-overvåke hele befolkningen, og diskusjonen så langt tyder på at flere
-av de andre partiene heller ikke har det. Mange av
-<a href="https://data.holderdeord.no/votes/1301946411e">de som stemte
-for Datalagringsdirektivet i Stortinget</a> (64 fra Arbeiderpartiet,
-25 fra Høyre) er fortsatt aktive og argumenterer fortsatt for å radere
-vekk mer av innbyggernes privatsfære.</p>
-
-<p>Når myndighetene demonstrerer sin mistillit til folket, tror jeg
-folket selv bør legge litt innsats i å verne sitt privatliv, ved å ta
-i bruk ende-til-ende-kryptert kommunikasjon med sine kjente og kjære,
-og begrense hvor mye privat informasjon som deles med uvedkommende.
-Det er jo ingenting som tyder på at myndighetene kommer til å være vår
-privatsfære.
-<a href="http://people.skolelinux.org/pere/blog/How_to_talk_with_your_loved_ones_in_private.html">Det
-er mange muligheter</a>. Selv har jeg litt sans for
-<a href="https://ring.cx/">Ring</a>, som er basert på p2p-teknologi
-uten sentral kontroll, er fri programvare, og støtter meldinger, tale
-og video. Systemet er tilgjengelig ut av boksen fra
-<a href="https://tracker.debian.org/pkg/ring">Debian</a> og
-<a href="https://launchpad.net/ubuntu/+source/ring">Ubuntu</a>, og det
-finnes pakker for Android, MacOSX og Windows. Foreløpig er det få
-brukere med Ring, slik at jeg også bruker
-<a href="https://signal.org/">Signal</a> som nettleserutvidelse.</p>
+ <title>Valutakrambod - A python and bitcoin love story</title>
+ <link>http://people.skolelinux.org/pere/blog/Valutakrambod___A_python_and_bitcoin_love_story.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Valutakrambod___A_python_and_bitcoin_love_story.html</guid>
+ <pubDate>Sat, 29 Sep 2018 22:20:00 +0200</pubDate>
+ <description><p>It would come as no surprise to anyone that I am interested in
+bitcoins and virtual currencies. I've been keeping an eye on virtual
+currencies for many years, and it is part of the reason a few months
+ago, I started writing a python library for collecting currency
+exchange rates and trade on virtual currency exchanges. I decided to
+name the end result valutakrambod, which perhaps can be translated to
+small currency shop.</p>
+
+<p>The library uses the tornado python library to handle HTTP and
+websocket connections, and provide a asynchronous system for
+connecting to and tracking several services. The code is available
+from
+<a href="http://github.com/petterreinholdtsen/valutakrambod">github</a>.</p>
+
+</p>There are two example clients of the library. One is very simple and
+list every updated buy/sell price received from the various services.
+This code is started by running bin/btc-rates and call the client code
+in valutakrambod/client.py. The simple client look like this:</p>
+
+<p><blockquote><pre>
+import functools
+import tornado.ioloop
+import valutakrambod
+class SimpleClient(object):
+ def __init__(self):
+ self.services = []
+ self.streams = []
+ pass
+ def newdata(self, service, pair, changed):
+ print("%-15s %s-%s: %8.3f %8.3f" % (
+ service.servicename(),
+ pair[0],
+ pair[1],
+ service.rates[pair]['ask'],
+ service.rates[pair]['bid'])
+ )
+ async def refresh(self, service):
+ await service.fetchRates(service.wantedpairs)
+ def run(self):
+ self.ioloop = tornado.ioloop.IOLoop.current()
+ self.services = valutakrambod.service.knownServices()
+ for e in self.services:
+ service = e()
+ service.subscribe(self.newdata)
+ stream = service.websocket()
+ if stream:
+ self.streams.append(stream)
+ else:
+ # Fetch information from non-streaming services immediately
+ self.ioloop.call_later(len(self.services),
+ functools.partial(self.refresh, service))
+ # as well as regularly
+ service.periodicUpdate(60)
+ for stream in self.streams:
+ stream.connect()
+ try:
+ self.ioloop.start()
+ except KeyboardInterrupt:
+ print("Interrupted by keyboard, closing all connections.")
+ pass
+ for stream in self.streams:
+ stream.close()
+</pre></blockquote></p>
+
+<p>The library client loops over all known "public" services,
+initialises it, subscribes to any updates from the service, checks and
+activates websocket streaming if the service provide it, and if no
+streaming is supported, fetches information from the service and sets
+up a periodic update every 60 seconds. The output from this client
+can look like this:</p>
+
+<p><blockquote><pre>
+Bl3p BTC-EUR: 5687.110 5653.690
+Bl3p BTC-EUR: 5687.110 5653.690
+Bl3p BTC-EUR: 5687.110 5653.690
+Hitbtc BTC-USD: 6594.560 6593.690
+Hitbtc BTC-USD: 6594.560 6593.690
+Bl3p BTC-EUR: 5687.110 5653.690
+Hitbtc BTC-USD: 6594.570 6593.690
+Bitstamp EUR-USD: 1.159 1.154
+Hitbtc BTC-USD: 6594.570 6593.690
+Hitbtc BTC-USD: 6594.580 6593.690
+Hitbtc BTC-USD: 6594.580 6593.690
+Hitbtc BTC-USD: 6594.580 6593.690
+Bl3p BTC-EUR: 5687.110 5653.690
+Paymium BTC-EUR: 5680.000 5620.240
+</pre></blockquote></p>
+
+<p>The exchange order book is tracked in addition to the best buy/sell
+price, for those that need to know the details.</p>
+
+<p>The other example client is focusing on providing a curses view
+with updated buy/sell prices as soon as they are received from the
+services. This code is located in bin/btc-rates-curses and activated
+by using the '-c' argument. Without the argument the "curses" output
+is printed without using curses, which is useful for debugging. The
+curses view look like this:</p>
+
+<p><blockquote><pre>
+ Name Pair Bid Ask Spr Ftcd Age
+ BitcoinsNorway BTCEUR 5591.8400 5711.0800 2.1% 16 nan 60
+ Bitfinex BTCEUR 5671.0000 5671.2000 0.0% 16 22 59
+ Bitmynt BTCEUR 5580.8000 5807.5200 3.9% 16 41 60
+ Bitpay BTCEUR 5663.2700 nan nan% 15 nan 60
+ Bitstamp BTCEUR 5664.8400 5676.5300 0.2% 0 1 1
+ Bl3p BTCEUR 5653.6900 5684.9400 0.5% 0 nan 19
+ Coinbase BTCEUR 5600.8200 5714.9000 2.0% 15 nan nan
+ Kraken BTCEUR 5670.1000 5670.2000 0.0% 14 17 60
+ Paymium BTCEUR 5620.0600 5680.0000 1.1% 1 7515 nan
+ BitcoinsNorway BTCNOK 52898.9700 54034.6100 2.1% 16 nan 60
+ Bitmynt BTCNOK 52960.3200 54031.1900 2.0% 16 41 60
+ Bitpay BTCNOK 53477.7833 nan nan% 16 nan 60
+ Coinbase BTCNOK 52990.3500 54063.0600 2.0% 15 nan nan
+ MiraiEx BTCNOK 52856.5300 54100.6000 2.3% 16 nan nan
+ BitcoinsNorway BTCUSD 6495.5300 6631.5400 2.1% 16 nan 60
+ Bitfinex BTCUSD 6590.6000 6590.7000 0.0% 16 23 57
+ Bitpay BTCUSD 6564.1300 nan nan% 15 nan 60
+ Bitstamp BTCUSD 6561.1400 6565.6200 0.1% 0 2 1
+ Coinbase BTCUSD 6504.0600 6635.9700 2.0% 14 nan 117
+ Gemini BTCUSD 6567.1300 6573.0700 0.1% 16 89 nan
+ Hitbtc+BTCUSD 6592.6200 6594.2100 0.0% 0 0 0
+ Kraken BTCUSD 6565.2000 6570.9000 0.1% 15 17 58
+ Exchangerates EURNOK 9.4665 9.4665 0.0% 16 107789 nan
+ Norgesbank EURNOK 9.4665 9.4665 0.0% 16 107789 nan
+ Bitstamp EURUSD 1.1537 1.1593 0.5% 4 5 1
+ Exchangerates EURUSD 1.1576 1.1576 0.0% 16 107789 nan
+ BitcoinsNorway LTCEUR 1.0000 49.0000 98.0% 16 nan nan
+ BitcoinsNorway LTCNOK 492.4800 503.7500 2.2% 16 nan 60
+ BitcoinsNorway LTCUSD 1.0221 49.0000 97.9% 15 nan nan
+ Norgesbank USDNOK 8.1777 8.1777 0.0% 16 107789 nan
+</pre></blockquote></p>
+
+<p>The code for this client is too complex for a simple blog post, so
+you will have to check out the git repository to figure out how it
+work. What I can tell is how the three last numbers on each line
+should be interpreted. The first is how many seconds ago information
+was received from the service. The second is how long ago, according
+to the service, the provided information was updated. The last is an
+estimate on how often the buy/sell values change.</p>
+
+<p>If you find this library useful, or would like to improve it, I
+would love to hear from you. Note that for some of the services I've
+implemented a trading API. It might be the topic of a future blog
+post.</p>
+
+<p>As usual, if you use Bitcoin and want to show your support of my
+activities, please send Bitcoin donations to my address
+<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
projects / homepage.git / blobdiff