Files
catalyst/zipline/data/treasuries.py
T
Scott Sanderson 8c38278783 ENH: Rewrite treasury loader using pandas.
Replaces our custom XML parsing with a single call to `pd.read_csv`
against the federal reserve's API.  This produces nearly identical
results as compared to the old loader, but it's dramatically simpler and
roughly 10x faster on my machine.

The average difference in magnitude between new and old is approximately
10e-7, and only one entry is different to a degree greater than the
number of significant figures provided by treasury.gov.

Additionally, the new loader correctly ignores Columbus Day of 2010, for
which the old loader erroneously produced an all-NaN row.

This also changes the interface that treasury modules modules are
required to implement. Modules must now supply a `get_treasury_data`
function that returns a `DataFrame` with a daily `DatetimeIndex` and a
column for each supported treasury duration.

Detailed comparison between results from new and old loader::

    from zipline.data.treasuries import get_treasury_data
    new = get_treasury_data() # New implementation
    old = pd.read_csv(  # Previously cached data
        '/home/ssanderson/.zipline/data/treasury_curves.csv'
        parse_dates=[0],
        index_col=0,
    )
    # These columns were unused.
    del old['tid']; del old['date']
    old = old.tz_localize('UTC')
    old.dropna(how='all')
    # old data erroneously contained an all-NaN entry for Columbus Day
    # in 2010.  Remove before comparing.
    old = old.dropna(how='all')

    In [25]: len(new) == len(old)
    Out[25]: True

    In [26]: abs(old - new).max()
    Out[26]:
    10year    2.000000e-04
    1month    6.938894e-18
    1year     1.000000e-04
    20year    1.000000e-04
    2year     2.000000e-04
    30year    1.000000e-04
    3month    1.000000e-03
    3year     1.000000e-04
    5year     1.387779e-17
    6month    1.000000e-04
    7year     1.000000e-04
    dtype: float64

    In [27]: abs(old - new).mean()
    Out[27]:
    10year    3.097414e-08
    1month    4.396534e-19
    1year     1.548707e-08
    20year    3.624502e-08
    2year     4.646120e-08
    30year    1.830496e-08
    3month    1.549427e-07
    3year     1.548707e-08
    5year     1.702619e-18
    6month    1.548707e-08
    7year     1.548707e-08
    dtype: float64

Since www.treasury.gov only reports values up to three significant
digits, we should only care about differences of greater than 1e-3.

There is exactly one such difference: the entry for the three month bond
on 1999-10-01::

    In [60]: new[(abs(new - old) >= 1e-3).any(axis=1)].T
    Out[60]:
    Time Period  1999-10-01 00:00:00+00:00
    1month                             NaN
    3month                          0.0498
    6month                          0.0501
    1year                           0.0530
    2year                           0.0573
    3year                           0.0583
    5year                           0.0590
    7year                           0.0622
    10year                          0.0600
    20year                          0.0657
    30year                          0.0615

    In [61]: old[(abs(new - old) >= 1e-3).any(axis=1)].T
    Out[61]:
            1999-10-01 00:00:00+00:00
            10year                     0.0600
            1month                        NaN
            1year                      0.0530
            20year                     0.0657
            2year                      0.0573
            30year                     0.0615
            3month                     0.0488
            3year                      0.0583
            5year                      0.0590
            6month                     0.0501
            7year                      0.0622

The US Treasury website (our old source) provides a value of 0.488 here,
whereas the Federal Reserve site (our new source) provides a value of
0.498.
2015-10-25 16:37:59 -04:00

90 lines
2.8 KiB
Python

#
# Copyright 2013 Quantopian, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import re
import numpy as np
import pandas as pd
def getkeys(d, keys):
return (d[key] for key in keys)
def parse_treasury_csv_column(column):
"""
Parse a treasury CSV column into a more human-readable format.
Columns are start with 'RIFLGFC', followed by Y or M (year or month),
followed by a two-digit number, followed by _N.B. We only care about the
middle two entries which we turn into a string like 3month or 30year.
"""
column_re = re.compile(
r"^(?P<prefix>RIFLGFC)"
"(?P<unit>[YM])"
"(?P<periods>[0-9]{2})"
"(?P<suffix>_N.B)$"
)
match = column_re.match(column)
if match is None:
raise ValueError("Couldn't parse CSV column %r." % column)
unit, periods = getkeys(match.groupdict(), ['unit', 'periods'])
# Roundtrip through int to coerce '06' into '6'.
return str(int(periods)) + ('year' if unit == 'Y' else 'month')
def get_treasury_data():
return pd.read_csv(
"http://www.federalreserve.gov/datadownload/Output.aspx"
"?rel=H15"
"&series=bf17364827e38702b42a58cf8eaa3f78"
"&lastObs="
"&from=" # An unbounded query is ~2x faster than specifying dates.
"&to="
"&filetype=csv"
"&label=omit"
"&layout=seriescolumn"
"&type=package",
skiprows=1, # First row is a useless header.
parse_dates=['Time Period'],
na_values=['ND'], # Presumably this stands for "No Data".
index_col=0,
).loc[
'1990': # Truncate down to 1990.
].dropna(
how='all'
).rename(
columns=parse_treasury_csv_column
).tz_localize('UTC') * 0.01
def dataconverter(s):
try:
return float(s) / 100
except:
return np.nan
def get_daily_10yr_treasury_data():
"""Download daily 10 year treasury rates from the Federal Reserve and
return a pandas.Series."""
url = "http://www.federalreserve.gov/datadownload/Output.aspx?rel=H15" \
"&series=bcb44e57fb57efbe90002369321bfb3f&lastObs=&from=&to=" \
"&filetype=csv&label=include&layout=seriescolumn"
return pd.read_csv(url, header=5, index_col=0, names=['DATE', 'BC_10YEAR'],
parse_dates=True, converters={1: dataconverter},
squeeze=True)