[QUIZ] Stock Portfolios (#41)

[Ruby Quiz]

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I'm a member of a local stock club. For those of you not familiar with such
clubs, they're just a group of people who pool resources (primarily knowledge,
research time, and finances) to purchase stocks.

My particular club makes use of a lot of technology for information and
communication. A recent request was a tool to practice investing. This is
especially helpful to inexperienced members. The idea is that they can pretend
to purchase a few stocks (preferably after studying their choices!) and then see
how they do over time.

This week's Ruby Quiz is to build this simple tool.

Here's a sample run to get the ideas flowing:

$ ./portfolio
Buy (symbol shares/dollars): PIXR $1000
You purchased 23 shares of PIXR for $991.53.
Buy (symbol shares/dollars): GOOG 3
You purchased 3 shares of GOOG for $887.55.
Buy (symbol shares/dollars):
+--------+--------+-----------+----------------+---------------+-----------+
| Symbol | Shares | Buy Price | Buy Date | Current Price | Gain/Loss |
+--------+--------+-----------+----------------+---------------+-----------+
| GOOG | 3 | $ 295.85 | 07/25/05 19:53 | $ 295.85 | $ 0.00 |
+--------+--------+-----------+----------------+---------------+-----------+
| PIXR | 23 | $ 43.11 | 07/25/05 19:53 | $ 43.11 | $ 0.00 |
+--------+--------+-----------+----------------+---------------+-----------+

Later, I can see how my shares are doing:

$ ./portfolio
+--------+--------+-----------+----------------+---------------+-----------+
| Symbol | Shares | Buy Price | Buy Date | Current Price | Gain/Loss |
+--------+--------+-----------+----------------+---------------+-----------+
| GOOG | 3 | $ 295.85 | 07/25/05 19:53 | $ 293.29 | $ -7.68 |
+--------+--------+-----------+----------------+---------------+-----------+
| PIXR | 23 | $ 43.11 | 07/25/05 19:53 | $ 43.44 | $ 7.59 |
+--------+--------+-----------+----------------+---------------+-----------+

Don't feel tied to this exact display or interface. Some interesting ideas
might be to show historical data before asking a user to confirm their choice,
or plot changes over regular intervals instead of just showing the initial and
current prices. If you think of something else, go for it.

I think this is a great quiz for beginners wanting to learn more about Ruby's
standard library. If that describes you, I encourage you to give it a try.
(Hint: Many web sites offer stock data, all you need do is figure out how to
get it...)

 

[Peter C. Verhage]

(Hint: Many web sites offer stock data, all you need do is figure out how to
get it...)

Possible "spoiler", but Yahoo makes it easy to get the stock data, see:
http://www.gummy-stuff.org/Yahoo-data.htm

Regards,

Peter

 

[James Edward Gray II]

Possible "spoiler", but Yahoo makes it easy to get the stock data,
see:
http://www.gummy-stuff.org/Yahoo-data.htm

Thanks for sharing. I wasn't aware of that service and it is trivial
to wrap:

$ ./stock_data -s -n -d1 -l1 -y -r AAPL GOOG PIXR RHAT
"AAPL","APPLE COMPUTER","8/9/2005",43.55,N/A,35.54
"GOOG","GOOGLE","8/9/2005",289.969,N/A,85.34
"PIXR","PIXAR","8/9/2005",43.65,N/A,26.73
"RHAT","RED HAT INC","8/9/2005",14.24,N/A,57.87
$ cat stock_data
#!/usr/local/bin/ruby -w

# Stock data via: http://www.gummy-stuff.org/Yahoo-data.htm

require "open-uri"

# parse options and symbols requested
data, stocks = ARGV.partition { |e| e[0] == ?- }
data = data.map { |tag| tag[/\w+/] }.join
stocks = stocks.join("+")

# fetch and print data
open "http://finance.yahoo.com/d/quotes.csv?s=#{stocks}&f=#{data}" do
|csv|
csv.each { |line| puts line }
end

__END__

James Edward Gray II

 

[James Edward Gray II]

This week's Ruby Quiz is to build this simple tool.

Here's the code used to create the quiz:

#!/usr/local/bin/ruby

require "yaml"
require "soap/rpc/driver"

server = SOAP::RPC:river.new( "http://services.xmethods.com/soap",
"urn:xmethods-delayed-quotes" )
server.add_method( "getQuote", "symbol" )

Struct.new("Shares", :symbol, :shares, rice, :date)

file_name = File.join(ENV["HOME"], ".portfolio.yaml")
portfolio = if File.exist? file_name
File.open(file_name) { |file| YAML.load(file) }
else
Hash.new
end

if portfolio.empty? or not ARGV.empty? and ARGV.first == "-p"
loop do
print "Buy (symbol shares/dollars): "
line = $stdin.gets.strip
break if line.empty?

ticker, amount = line.split
price = server.getQuote(ticker)
if price <= 0
puts "Unable to fetch a price for that ticker symbol."
next
end

if amount =~ /^\$(\d+)$/
dollars = Integer($1)
shares = (dollars / price).to_i
elsif amount =~ /^[1-9]\d*$/
shares = Integer(amount)
else
puts "Unknown amount format."
next
end

if shares.zero?
puts "You can't purchase any shares for that amount."
next
else
date = Time.now.strftime("%m/%d/%y %H:%M")
buy = Struct::Shares.new(ticker, shares, price, date)
portfolio[buy.symbol] = buy

puts "You purchased #{buy.shares} shares of #
{buy.symbol} " +
"for $#{"%.2f" % (buy.shares * price)}."
end
end

File.open(file_name, "w") { |file| YAML.dump(portfolio, file) }
end

output = [%w{Symbol Shares Buy\ Price Buy\ Date Current\ Price Gain/
Loss}]
portfolio.each do |ticker, details|
current = server.getQuote(ticker)
output << [ ticker, details.shares, details.price, details.date,
current,
details.shares * current - details.shares *
details.price ]
end

widths = Array.new(output.first.size, 0)
output.each do |row|
row.each_index do |index|
width = if row[index].is_a? Float
("%.2f" % row[index]).length + 1
else
row[index].to_s.length
end
widths[index] = width if width > widths[index]
end
end

border = "+-" + widths.map { |width| "-" * width }.join("-+-") + "-+"
template = ("| " + output.last.map do |column|
case column
when Float
"$%#{widths.shift - 1}.2f"
when Integer
"%#{widths.shift}d"
else
"%#{widths.shift}s"
end
end.join(" | ") + " |").sub(/\A\| %/, "| %-")
puts border
puts template.gsub(/ \| \$?%(\d+)(?:\.\d+)?[sdf]/, " | %\\1s") %
output.first
output[1..-1].sort.each do |row|
puts border
puts template % row
end
puts border

__END__

James Edward Gray II

 

[Jeffrey Moss]

I use a web service that uses yahoo, I always thought this was dirty though,
I wanted a web service but not one that ripped it off some website.

require 'soap/rpc/driver'

driver = SOAP::RPC:river.new( 'http://services.xmethods.com/soap',
'urn:xmethods-delayed-quotes' )
driver.add_method( 'getQuote', 'a_string' )
driver.getQuote('GOOG')

-Jeff

----- Original Message -----
From: "James Edward Gray II" <[email protected]>
To: "ruby-talk ML" <[email protected]>
Sent: Tuesday, August 09, 2005 9:50 AM
Subject: Re: [SOLUTION] Stock Portfolios (#41)

Possible "spoiler", but Yahoo makes it easy to get the stock data, see:
http://www.gummy-stuff.org/Yahoo-data.htm

Thanks for sharing. I wasn't aware of that service and it is trivial to
wrap:

$ ./stock_data -s -n -d1 -l1 -y -r AAPL GOOG PIXR RHAT
"AAPL","APPLE COMPUTER","8/9/2005",43.55,N/A,35.54
"GOOG","GOOGLE","8/9/2005",289.969,N/A,85.34
"PIXR","PIXAR","8/9/2005",43.65,N/A,26.73
"RHAT","RED HAT INC","8/9/2005",14.24,N/A,57.87
$ cat stock_data
#!/usr/local/bin/ruby -w

# Stock data via: http://www.gummy-stuff.org/Yahoo-data.htm

require "open-uri"

# parse options and symbols requested
data, stocks = ARGV.partition { |e| e[0] == ?- }
data = data.map { |tag| tag[/\w+/] }.join
stocks = stocks.join("+")

# fetch and print data
open "http://finance.yahoo.com/d/quotes.csv?s=#{stocks}&f=#{data}" do
|csv|
csv.each { |line| puts line }
end

__END__

James Edward Gray II

 

[Adam Sanderson]

Here's my solution:
http://staff.washington.edu/netghost/stocks.rb

The application bit is a little unpolished, but it has some neat
features:
-Lookup stocks:
view goog, msft
-Buy/Sell multiple stocks:
buy 10 goog, 20 msft
-Get a history of transactions:
history goog

Anyways, this was pretty fun, and I even found a compelling use for
OpenStruct, neat.
.adam

 

[email55555]

if portfolio.empty? or not ARGV.empty? and ARGV.first == "-p"

Typo error ?

The way you wrote:
if portfolio.empty? or not ARGV.empty? and ARGV.first == "-p"
Will treat like:
if (portfolio.empty? or not ARGV.empty?) and ARGV.first == "-p"

I guess you would like to say:
if portfolio.empty? or (not ARGV.empty? and ARGV.first == "-p")

Note:
&& has higher precedence than ||
but "or" "and" both are the same precedence.

 

[James Edward Gray II]

Typo error ?

The way you wrote:
if portfolio.empty? or not ARGV.empty? and ARGV.first == "-p"
Will treat like:
if (portfolio.empty? or not ARGV.empty?) and ARGV.first == "-p"

I guess you would like to say:
if portfolio.empty? or (not ARGV.empty? and ARGV.first == "-p")

Note:
&& has higher precedence than ||
but "or" "and" both are the same precedence.

You're right and I should know better. Thanks!

James Edward Gray II