Missing decimals in the code - some suggestions?

[hmjeltevik]

Hi!

I am using ystockquote with the following code:

def get_historical_prices(symbol, start_date, end_date):
"""
Get historical prices for the given ticker symbol.
Date format is 'YYYYMMDD'

Returns a nested list.
"""
url = 'http://ichart.yahoo.com/table.csv?s=%s&' % symbol + \
'd=%s&' % str(int(end_date[4:6]) - 1) + \
'e=%s&' % str(int(end_date[6:8])) + \
'f=%s&' % str(int(end_date[0:4])) + \
'g=d&' + \
'a=%s&' % str(int(start_date[4:6]) - 1) + \
'b=%s&' % str(int(start_date[6:8])) + \
'c=%s&' % str(int(start_date[0:4])) + \
'ignore=.csv'
days = urllib.urlopen(url).readlines()
data = [day[:-2].split(',') for day in days]
return data

This code prints the data, but only 2 decimals. I need to print out 4 decimals.

print ystockquote.get_historical_prices('EURUSD=X','20120101','20120301')

Some suggestions?

 

[Ian Kelly]

Hi!

I am using ystockquote with the following code:

def get_historical_prices(symbol, start_date, end_date):
"""
Get historical prices for the given ticker symbol.
Date format is 'YYYYMMDD'

Returns a nested list.
"""
url = 'http://ichart.yahoo.com/table.csv?s=%s&' % symbol + \
'd=%s&' % str(int(end_date[4:6]) - 1) + \
'e=%s&' % str(int(end_date[6:8])) + \
'f=%s&' % str(int(end_date[0:4])) + \
'g=d&' + \
'a=%s&' % str(int(start_date[4:6]) - 1) + \
'b=%s&' % str(int(start_date[6:8])) + \
'c=%s&' % str(int(start_date[0:4])) + \
'ignore=.csv'
days = urllib.urlopen(url).readlines()
data = [day[:-2].split(',') for day in days]
return data

This code prints the data, but only 2 decimals. I need to print out 4 decimals.

print ystockquote.get_historical_prices('EURUSD=X','20120101','20120301')

Some suggestions?

This isn't a Python question. If you take a look at the csv file that
you download from Yahoo, you will see that it only contains 2 digits
of precision. There's no way to make Python print out 4 digits of
precision when it is only provided with 2. You will need to find out
if there is a way to ask for more precision in the Yahoo API.

 

[MRAB]

Hi!

I am using ystockquote with the following code:

def get_historical_prices(symbol, start_date, end_date):
"""
Get historical prices for the given ticker symbol.
Date format is 'YYYYMMDD'

Returns a nested list.
"""
url = 'http://ichart.yahoo.com/table.csv?s=%s&' % symbol + \
'd=%s&' % str(int(end_date[4:6]) - 1) + \
'e=%s&' % str(int(end_date[6:8])) + \
'f=%s&' % str(int(end_date[0:4])) + \
'g=d&' + \
'a=%s&' % str(int(start_date[4:6]) - 1) + \
'b=%s&' % str(int(start_date[6:8])) + \
'c=%s&' % str(int(start_date[0:4])) + \
'ignore=.csv'
days = urllib.urlopen(url).readlines()
data = [day[:-2].split(',') for day in days]
return data

This code prints the data, but only 2 decimals. I need to print out 4 decimals.

print ystockquote.get_historical_prices('EURUSD=X','20120101','20120301')

Some suggestions?

The code prints what it receives; the data it receives has only 2
decimal places.

This question:

http://stackoverflow.com/questions/...rices-queries-how-to-change-default-precision

says that it's Yahoo doing the rounding to 2 decimal places.

It looks like you'll have to find another way to get what you want.

 

[Terry Jan Reedy]

Hi!

I am using ystockquote with the following code:

def get_historical_prices(symbol, start_date, end_date):
"""
Get historical prices for the given ticker symbol.
Date format is 'YYYYMMDD'

Returns a nested list.
"""
url = 'http://ichart.yahoo.com/table.csv?s=%s&' % symbol + \
'd=%s&' % str(int(end_date[4:6]) - 1) + \
'e=%s&' % str(int(end_date[6:8])) + \
'f=%s&' % str(int(end_date[0:4])) + \
'g=d&' + \
'a=%s&' % str(int(start_date[4:6]) - 1) + \
'b=%s&' % str(int(start_date[6:8])) + \
'c=%s&' % str(int(start_date[0:4])) + \
'ignore=.csv'
days = urllib.urlopen(url).readlines()
data = [day[:-2].split(',') for day in days]
return data

This code prints the data, but only 2 decimals. I need to print out 4 decimals.

As far as I know, prices are only defined to the nearest penny* (2
decimals) so I don't know what more you expect.

*Not too long ago, prices were in 1/8ths of a dollar. Market makers
complained about decimalization because it would squeeze the spread that
they profited from -- which it did.

 

[Steven D'Aprano]

This isn't a Python question. If you take a look at the csv file that
you download from Yahoo, you will see that it only contains 2 digits of
precision. There's no way to make Python print out 4 digits of
precision when it is only provided with 2.

Pish posh! It's easy to add extra precision.


py> value = "2.57"
py> import random
py> n = random.randrange(0, 100)
py> value += "%2d" % n
py> print value
2.5791


On average, your numbers will only be off by five parts in a thousand. If
the values represent dollars, that's half a cent. Who care about half a
cent?



Adding-spurious-precision-for-fun-and-profit-ly y'rs,

 

[Ian Kelly]

Pish posh! It's easy to add extra precision.

It's easy to add extra /digits/. Adding extra precision is much harder. ;-)