from statsmodels.compat.python import (range, StringIO, urlopen, HTTPError,
lrange, cPickle, urljoin)
import sys
import shutil
from os import environ
from os import makedirs
from os.path import expanduser
from os.path import exists
from os.path import join
import numpy as np
from numpy import array
from pandas import read_csv, DataFrame, Index
[docs]def webuse(data, baseurl='http://www.stata-press.com/data/r11/', as_df=True):
"""
Parameters
----------
data : str
Name of dataset to fetch.
baseurl : str
The base URL to the stata datasets.
as_df : bool
If True, returns a `pandas.DataFrame`
Returns
-------
dta : Record Array
A record array containing the Stata dataset.
Examples
--------
>>> dta = webuse('auto')
Notes
-----
Make sure baseurl has trailing forward slash. Doesn't do any
error checking in response URLs.
"""
# lazy imports
from statsmodels.iolib import genfromdta
url = urljoin(baseurl, data+'.dta')
dta = urlopen(url)
dta = StringIO(dta.read()) # make it truly file-like
if as_df: # could make this faster if we don't process dta twice?
return DataFrame.from_records(genfromdta(dta))
else:
return genfromdta(dta)
class Dataset(dict):
def __init__(self, **kw):
# define some default attributes, so pylint can find them
self.endog = None
self.exog = None
self.data = None
self.names = None
dict.__init__(self, kw)
self.__dict__ = self
# Some datasets have string variables. If you want a raw_data
# attribute you must create this in the dataset's load function.
try: # some datasets have string variables
self.raw_data = self.data.view((float, len(self.names)))
except:
pass
def __repr__(self):
return str(self.__class__)
def process_recarray(data, endog_idx=0, exog_idx=None, stack=True, dtype=None):
names = list(data.dtype.names)
if isinstance(endog_idx, int):
endog = array(data[names[endog_idx]], dtype=dtype)
endog_name = names[endog_idx]
endog_idx = [endog_idx]
else:
endog_name = [names[i] for i in endog_idx]
if stack:
endog = np.column_stack(data[field] for field in endog_name)
else:
endog = data[endog_name]
if exog_idx is None:
exog_name = [names[i] for i in range(len(names))
if i not in endog_idx]
else:
exog_name = [names[i] for i in exog_idx]
if stack:
exog = np.column_stack(data[field] for field in exog_name)
else:
exog = data[exog_name]
if dtype:
endog = endog.astype(dtype)
exog = exog.astype(dtype)
dataset = Dataset(data=data, names=names, endog=endog, exog=exog,
endog_name=endog_name, exog_name=exog_name)
return dataset
def process_recarray_pandas(data, endog_idx=0, exog_idx=None, dtype=None,
index_idx=None):
data = DataFrame(data, dtype=dtype)
names = data.columns
if isinstance(endog_idx, int):
endog_name = names[endog_idx]
endog = data[endog_name]
if exog_idx is None:
exog = data.drop([endog_name], axis=1)
else:
exog = data.filter(names[exog_idx])
else:
endog = data.ix[:, endog_idx]
endog_name = list(endog.columns)
if exog_idx is None:
exog = data.drop(endog_name, axis=1)
elif isinstance(exog_idx, int):
exog = data.filter([names[exog_idx]])
else:
exog = data.filter(names[exog_idx])
if index_idx is not None: # NOTE: will have to be improved for dates
endog.index = Index(data.ix[:, index_idx])
exog.index = Index(data.ix[:, index_idx])
data = data.set_index(names[index_idx])
exog_name = list(exog.columns)
dataset = Dataset(data=data, names=list(names), endog=endog, exog=exog,
endog_name=endog_name, exog_name=exog_name)
return dataset
def _maybe_reset_index(data):
"""
All the Rdatasets have the integer row.labels from R if there is no
real index. Strip this for a zero-based index
"""
if data.index.equals(Index(lrange(1, len(data) + 1))):
data = data.reset_index(drop=True)
return data
def _get_cache(cache):
if cache is False:
# do not do any caching or load from cache
cache = None
elif cache is True: # use default dir for cache
cache = get_data_home(None)
else:
cache = get_data_home(cache)
return cache
def _cache_it(data, cache_path):
if sys.version_info[0] >= 3:
# for some reason encode("zip") won't work for me in Python 3?
import zlib
# use protocol 2 so can open with python 2.x if cached in 3.x
open(cache_path, "wb").write(zlib.compress(cPickle.dumps(data,
protocol=2)))
else:
open(cache_path, "wb").write(cPickle.dumps(data).encode("zip"))
def _open_cache(cache_path):
if sys.version_info[0] >= 3:
# NOTE: don't know why but decode('zip') doesn't work on my
# Python 3 build
import zlib
data = zlib.decompress(open(cache_path, 'rb').read())
# return as bytes object encoded in utf-8 for cross-compat of cached
data = cPickle.loads(data).encode('utf-8')
else:
data = open(cache_path, 'rb').read().decode('zip')
data = cPickle.loads(data)
return data
def _urlopen_cached(url, cache):
"""
Tries to load data from cache location otherwise downloads it. If it
downloads the data and cache is not None then it will put the downloaded
data in the cache path.
"""
from_cache = False
if cache is not None:
cache_path = join(cache,
url.split("://")[-1].replace('/', ',') + ".zip")
try:
data = _open_cache(cache_path)
from_cache = True
except:
pass
# not using the cache or didn't find it in cache
if not from_cache:
data = urlopen(url).read()
if cache is not None: # then put it in the cache
_cache_it(data, cache_path)
return data, from_cache
def _get_data(base_url, dataname, cache, extension="csv"):
url = base_url + (dataname + ".%s") % extension
try:
data, from_cache = _urlopen_cached(url, cache)
except HTTPError as err:
if '404' in str(err):
raise ValueError("Dataset %s was not found." % dataname)
else:
raise err
data = data.decode('utf-8', 'strict')
return StringIO(data), from_cache
def _get_dataset_meta(dataname, package, cache):
# get the index, you'll probably want this cached because you have
# to download info about all the data to get info about any of the data...
index_url = ("https://raw.github.com/vincentarelbundock/Rdatasets/master/"
"datasets.csv")
data, _ = _urlopen_cached(index_url, cache)
# Python 3
if sys.version[0] == '3': # pragma: no cover
data = data.decode('utf-8', 'strict')
index = read_csv(StringIO(data))
idx = np.logical_and(index.Item == dataname, index.Package == package)
dataset_meta = index.ix[idx]
return dataset_meta["Title"].item()
[docs]def get_rdataset(dataname, package="datasets", cache=False):
"""download and return R dataset
Parameters
----------
dataname : str
The name of the dataset you want to download
package : str
The package in which the dataset is found. The default is the core
'datasets' package.
cache : bool or str
If True, will download this data into the STATSMODELS_DATA folder.
The default location is a folder called statsmodels_data in the
user home folder. Otherwise, you can specify a path to a folder to
use for caching the data. If False, the data will not be cached.
Returns
-------
dataset : Dataset instance
A `statsmodels.data.utils.Dataset` instance. This objects has
attributes::
* data - A pandas DataFrame containing the data
* title - The dataset title
* package - The package from which the data came
* from_cache - Whether not cached data was retrieved
* __doc__ - The verbatim R documentation.
Notes
-----
If the R dataset has an integer index. This is reset to be zero-based.
Otherwise the index is preserved. The caching facilities are dumb. That
is, no download dates, e-tags, or otherwise identifying information
is checked to see if the data should be downloaded again or not. If the
dataset is in the cache, it's used.
"""
# NOTE: use raw github bc html site might not be most up to date
data_base_url = ("https://raw.github.com/vincentarelbundock/Rdatasets/"
"master/csv/"+package+"/")
docs_base_url = ("https://raw.github.com/vincentarelbundock/Rdatasets/"
"master/doc/"+package+"/rst/")
cache = _get_cache(cache)
data, from_cache = _get_data(data_base_url, dataname, cache)
data = read_csv(data, index_col=0)
data = _maybe_reset_index(data)
title = _get_dataset_meta(dataname, package, cache)
doc, _ = _get_data(docs_base_url, dataname, cache, "rst")
return Dataset(data=data, __doc__=doc.read(), package=package, title=title,
from_cache=from_cache)
# The below function were taken from sklearn
[docs]def get_data_home(data_home=None):
"""Return the path of the statsmodels data dir.
This folder is used by some large dataset loaders to avoid
downloading the data several times.
By default the data dir is set to a folder named 'statsmodels_data'
in the user home folder.
Alternatively, it can be set by the 'STATSMODELS_DATA' environment
variable or programatically by giving an explit folder path. The
'~' symbol is expanded to the user home folder.
If the folder does not already exist, it is automatically created.
"""
if data_home is None:
data_home = environ.get('STATSMODELS_DATA',
join('~', 'statsmodels_data'))
data_home = expanduser(data_home)
if not exists(data_home):
makedirs(data_home)
return data_home
[docs]def clear_data_home(data_home=None):
"""Delete all the content of the data home cache."""
data_home = get_data_home(data_home)
shutil.rmtree(data_home)
