WyomingUpperAir.to_float() - Code Metrics - Inspection of "ENH: Add cached copy of data for sounding." - Unidata/MetPy - Measure and Improve Code Quality continuously with Scrutinizer

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created 2016-11-13 21:38 UTC

WyomingUpperAir.to_float() A

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loc	5
rs	9.4285

# Copyright (c) 2016 MetPy Developers.
# Distributed under the terms of the BSD 3-Clause License.
# SPDX-License-Identifier: BSD-3-Clause

from io import BytesIO
import json
try:
    from urllib.request import urlopen
except ImportError:
    from urllib2 import urlopen

import numpy as np

from ..calc import get_wind_components
from .cdm import Dataset
from .tools import UnitLinker
from ..package_tools import Exporter

exporter = Exporter(globals())


@exporter.export
def get_upper_air_data(time, site_id, source='wyoming', **kwargs):
    r"""Download and parse upper air observations from an online archive.

    Parameters
    ----------
    time : datetime
        The date and time of the desired observation.

    site_id : str
        The three letter ICAO identifier of the station for which data should be
        downloaded.

    source : str
        The archive to use as a source of data. Current can be one of 'wyoming' or 'iastate'.
        Defaults to 'wyoming'.

    kwargs
        Arbitrary keyword arguments to use to initialize source

    Returns
    -------
        :class:`metpy.io.cdm.Dataset` containing the data
    """
    sources = dict(wyoming=WyomingUpperAir, iastate=IAStateUpperAir)
    src = sources.get(source)
    if src is None:
        raise ValueError('Unknown source for data: {0}'.format(str(source)))

    fobj = src.get_data(time, site_id, **kwargs)
    info = src.parse(fobj)

    ds = Dataset()
    ds.createDimension('pressure', len(info['p'][0]))

    # Simplify the process of creating variables that wrap the parsed arrays and can
    # return appropriate units attached to data
    def add_unit_var(name, std_name, arr, unit):
        var = ds.createVariable(name, arr.dtype, ('pressure',), wrap_array=arr)
        var.standard_name = std_name
        var.units = unit
        ds.variables[name] = UnitLinker(var)
        return var

    # Add variables for all the data columns
    for key, name, std_name in [('p', 'pressure', 'air_pressure'),
                                ('t', 'temperature', 'air_temperature'),
                                ('td', 'dewpoint', 'dew_point_temperature')]:
        data, units = info[key]
        add_unit_var(name, std_name, data, units)

    direc, spd, spd_units = info['wind']
    u, v = get_wind_components(spd, np.deg2rad(direc))
    add_unit_var('u_wind', 'eastward_wind', u, spd_units)
    add_unit_var('v_wind', 'northward_wind', v, spd_units)

    return ds


class UseSampleData(object):
    r"""Class to temporarily point to local sample data instead of downloading."""
    url_map = {r'http://weather.uwyo.edu/cgi-bin/sounding?region=naconf&TYPE=TEXT%3ALIST'
               r'&YEAR=1999&MONTH=05&FROM=0400&TO=0400&STNM=OUN': 'may3_sounding.txt',
               r'http://weather.uwyo.edu/cgi-bin/sounding?region=naconf&TYPE=TEXT%3ALIST'
               r'&YEAR=2013&MONTH=01&FROM=2012&TO=2012&STNM=OUN': 'sounding_data.txt',
               r'http://mesonet.agron.iastate.edu/json/raob.py?ts=201607301200'
               r'&station=KDEN': 'sounding_iastate.txt',
               r'http://weather.uwyo.edu/cgi-bin/sounding?region=naconf&TYPE=TEXT%3ALIST'
               r'&YEAR=2010&MONTH=12&FROM=0912&TO=0912&STNM=BOI': 'sounding_wyoming_upper.txt'}

    def __init__(self):
        r"""Initialize the wrapper."""
        self._urlopen = urlopen

    def _wrapped_urlopen(self, url):
        r"""Method to wrap urlopen and look to see if the request should be redirected."""
        from metpy.cbook import get_test_data

        filename = self.url_map.get(url)

        if filename is None:
            return self._urlopen(url)
        else:
            return open(get_test_data(filename, False), 'rb')

    def __enter__(self):
        global urlopen
        urlopen = self._wrapped_urlopen

    def __exit__(self, exc_type, exc_val, exc_tb):
        global urlopen
        urlopen = self._urlopen


class WyomingUpperAir(object):
    r"""Download and parse data from the University of Wyoming's upper air archive."""

    @staticmethod
    def get_data(time, site_id, region='naconf'):
        r"""Download data from the University of Wyoming's upper air archive.

        Parameters
        ----------
        time : datetime
            Date and time for which data should be downloaded
        site_id : str
            Site id for which data should be downloaded
        region : str
            The region in which the station resides. Defaults to `naconf`.

        Returns
        -------
        a file-like object from which to read the data
        """
        url = ('http://weather.uwyo.edu/cgi-bin/sounding?region={region}&TYPE=TEXT%3ALIST'
               '&YEAR={time:%Y}&MONTH={time:%m}&FROM={time:%d%H}&TO={time:%d%H}'
               '&STNM={stid}').format(region=region, time=time, stid=site_id)
        fobj = urlopen(url)
        data = fobj.read()

        # Since the archive text format is embedded in HTML, look for the <PRE> tags
        data_start = data.find(b'<PRE>')
        data_end = data.find(b'</PRE>', data_start)

        # Grab the stuff *between* the <PRE> tags -- 6 below is len('<PRE>\n')
        buf = data[data_start + 6:data_end]
        return BytesIO(buf.strip())

    @staticmethod
    def parse(fobj):
        r"""Parse Wyoming Upper Air Data.

        This parses the particular tabular layout of upper air data used by the University of
        Wyoming upper air archive.

        Parameters
        ----------
        fobj : file-like object
            The file-like object from which the data should be read. This needs to be set up
            to return bytes when read, not strings.

        Returns
        -------
        dict of information used by :func:`get_upper_air_data`
        """
        def to_float(s):
            # Remove all whitespace and replace empty values with NaN
            if not s.strip():
                s = 'nan'
            return float(s)

        # Skip the row of dashes and column names
        for _ in range(2):
            fobj.readline()

        # Parse the actual data, only grabbing the columns for pressure, T/Td, and wind
        unit_strs = ['degC' if u == 'C' else u
                     for u in fobj.readline().decode('ascii').split()]

        # Skip last header row of dashes
        fobj.readline()

        # Initiate lists for variables
        arr_data = []

        # Read all lines of data and append to lists only if there is some data
        for row in fobj:
            level = to_float(row[0:7])
            values = (to_float(row[14:21]), to_float(row[21:28]), to_float(row[42:49]),
                      to_float(row[49:56]))

            if any(np.invert(np.isnan(values))):
                arr_data.append((level,) + values)

        p, t, td, direc, spd = np.array(arr_data).T

        return dict(p=(p, unit_strs[0]), t=(t, unit_strs[2]), td=(td, unit_strs[3]),
                    wind=(direc, spd, unit_strs[7]))


class IAStateUpperAir(object):
    r"""Download and parse data from the Iowa State's upper air archive."""
    @staticmethod
    def get_data(time, site_id):
        r"""Download data from the Iowa State's upper air archive.

        Parameters
        ----------
        time : datetime
            Date and time for which data should be downloaded
        site_id : str
            Site id for which data should be downloaded

        Returns
        -------
        a file-like object from which to read the data
        """
        url = ('http://mesonet.agron.iastate.edu/json/raob.py?ts={time:%Y%m%d%H}00'
               '&station={stid}').format(time=time, stid=site_id)

        return urlopen(url)

    @staticmethod
    def parse(fobj):
        r"""Parse Iowa State Upper Air Data.

        This parses the JSON formatted data returned by the Iowa State upper air data archive.

        Parameters
        ----------
        fobj : file-like object
            The file-like object from which the data should be read. This needs to be set up
            to return bytes when read, not strings.

        Returns
        -------
        dict of information used by :func:`get_upper_air_data`
        """
        json_data = json.loads(fobj.read().decode('utf-8'))['profiles'][0]['profile']

        data = dict()
        for pt in json_data:
            for field in ('drct', 'dwpc', 'pres', 'sknt', 'tmpc'):
                data.setdefault(field, []).append(np.nan if pt[field] is None else pt[field])

        ret = dict(p=(np.array(data['pres']), 'mbar'), t=(np.array(data['tmpc']), 'degC'),
                   td=(np.array(data['dwpc']), 'degC'),
                   wind=(np.array(data['drct']), np.array(data['sknt']), 'knot'))

        return ret


1			# Copyright (c) 2016 MetPy Developers.
2			# Distributed under the terms of the BSD 3-Clause License.
3			# SPDX-License-Identifier: BSD-3-Clause
4
5			from io import BytesIO
6			import json
7			try:
8			from urllib.request import urlopen
9			except ImportError:
10			from urllib2 import urlopen
11
12			import numpy as np
13
14			from ..calc import get_wind_components
15			from .cdm import Dataset
16			from .tools import UnitLinker
17			from ..package_tools import Exporter
18
19			exporter = Exporter(globals())
20
21
22			@exporter.export
23			def get_upper_air_data(time, site_id, source='wyoming', **kwargs):
24			r"""Download and parse upper air observations from an online archive.
25
26			Parameters
27			----------
28			time : datetime
29			The date and time of the desired observation.
30
31			site_id : str
32			The three letter ICAO identifier of the station for which data should be
33			downloaded.
34
35			source : str
36			The archive to use as a source of data. Current can be one of 'wyoming' or 'iastate'.
37			Defaults to 'wyoming'.
38
39			kwargs
40			Arbitrary keyword arguments to use to initialize source
41
42			Returns
43			-------
44			:class:`metpy.io.cdm.Dataset` containing the data
45			"""
46			sources = dict(wyoming=WyomingUpperAir, iastate=IAStateUpperAir)
47			src = sources.get(source)
48			if src is None:
49			raise ValueError('Unknown source for data: {0}'.format(str(source)))
50
51			fobj = src.get_data(time, site_id, **kwargs)
52			info = src.parse(fobj)
53
54			ds = Dataset()
55			ds.createDimension('pressure', len(info['p'][0]))
56
57			# Simplify the process of creating variables that wrap the parsed arrays and can
58			# return appropriate units attached to data
59			def add_unit_var(name, std_name, arr, unit):
60			var = ds.createVariable(name, arr.dtype, ('pressure',), wrap_array=arr)
61			var.standard_name = std_name
62			var.units = unit
63			ds.variables[name] = UnitLinker(var)
64			return var
65
66			# Add variables for all the data columns
67			for key, name, std_name in [('p', 'pressure', 'air_pressure'),
68			('t', 'temperature', 'air_temperature'),
69			('td', 'dewpoint', 'dew_point_temperature')]:
70			data, units = info[key]
71			add_unit_var(name, std_name, data, units)
72
73			direc, spd, spd_units = info['wind']
74			u, v = get_wind_components(spd, np.deg2rad(direc))
75			add_unit_var('u_wind', 'eastward_wind', u, spd_units)
76			add_unit_var('v_wind', 'northward_wind', v, spd_units)
77
78			return ds
79
80
81			class UseSampleData(object):
82			r"""Class to temporarily point to local sample data instead of downloading."""
83			url_map = {r'http://weather.uwyo.edu/cgi-bin/sounding?region=naconf&TYPE=TEXT%3ALIST'
84			r'&YEAR=1999&MONTH=05&FROM=0400&TO=0400&STNM=OUN': 'may3_sounding.txt',
85			r'http://weather.uwyo.edu/cgi-bin/sounding?region=naconf&TYPE=TEXT%3ALIST'
86			r'&YEAR=2013&MONTH=01&FROM=2012&TO=2012&STNM=OUN': 'sounding_data.txt',
87			r'http://mesonet.agron.iastate.edu/json/raob.py?ts=201607301200'
88			r'&station=KDEN': 'sounding_iastate.txt',
89			r'http://weather.uwyo.edu/cgi-bin/sounding?region=naconf&TYPE=TEXT%3ALIST'
90			r'&YEAR=2010&MONTH=12&FROM=0912&TO=0912&STNM=BOI': 'sounding_wyoming_upper.txt'}
91
92			def __init__(self):
93			r"""Initialize the wrapper."""
94			self._urlopen = urlopen
95
96			def _wrapped_urlopen(self, url):
97			r"""Method to wrap urlopen and look to see if the request should be redirected."""
98			from metpy.cbook import get_test_data
99
100			filename = self.url_map.get(url)
101
102			if filename is None:
103			return self._urlopen(url)
104			else:
105			return open(get_test_data(filename, False), 'rb')
106
107			def __enter__(self):
108			global urlopen
109			urlopen = self._wrapped_urlopen
110
111			def __exit__(self, exc_type, exc_val, exc_tb):
112			global urlopen
113			urlopen = self._urlopen
114
115
116			class WyomingUpperAir(object):
117			r"""Download and parse data from the University of Wyoming's upper air archive."""
118
119			@staticmethod
120			def get_data(time, site_id, region='naconf'):
121			r"""Download data from the University of Wyoming's upper air archive.
122
123			Parameters
124			----------
125			time : datetime
126			Date and time for which data should be downloaded
127			site_id : str
128			Site id for which data should be downloaded
129			region : str
130			The region in which the station resides. Defaults to `naconf`.
131
132			Returns
133			-------
134			a file-like object from which to read the data
135			"""
136			url = ('http://weather.uwyo.edu/cgi-bin/sounding?region={region}&TYPE=TEXT%3ALIST'
137			'&YEAR={time:%Y}&MONTH={time:%m}&FROM={time:%d%H}&TO={time:%d%H}'
138			'&STNM={stid}').format(region=region, time=time, stid=site_id)
139			fobj = urlopen(url)
140			data = fobj.read()
141
142			# Since the archive text format is embedded in HTML, look for the <PRE> tags
143			data_start = data.find(b'<PRE>')
144			data_end = data.find(b'</PRE>', data_start)
145
146			# Grab the stuff between the <PRE> tags -- 6 below is len('<PRE>\n')
147			buf = data[data_start + 6:data_end]
148			return BytesIO(buf.strip())
149
150			@staticmethod
151			def parse(fobj):
152			r"""Parse Wyoming Upper Air Data.
153
154			This parses the particular tabular layout of upper air data used by the University of
155			Wyoming upper air archive.
156
157			Parameters
158			----------
159			fobj : file-like object
160			The file-like object from which the data should be read. This needs to be set up
161			to return bytes when read, not strings.
162
163			Returns
164			-------
165			dict of information used by :func:`get_upper_air_data`
166			"""
167			def to_float(s):
168			# Remove all whitespace and replace empty values with NaN
169			if not s.strip():
170			s = 'nan'
171			return float(s)
172
173			# Skip the row of dashes and column names
174			for _ in range(2):
175			fobj.readline()
176
177			# Parse the actual data, only grabbing the columns for pressure, T/Td, and wind
178			unit_strs = ['degC' if u == 'C' else u
179			for u in fobj.readline().decode('ascii').split()]
180
181			# Skip last header row of dashes
182			fobj.readline()
183
184			# Initiate lists for variables
185			arr_data = []
186
187			# Read all lines of data and append to lists only if there is some data
188			for row in fobj:
189			level = to_float(row[0:7])
190			values = (to_float(row[14:21]), to_float(row[21:28]), to_float(row[42:49]),
191			to_float(row[49:56]))
192
193			if any(np.invert(np.isnan(values))):
194			arr_data.append((level,) + values)
195
196			p, t, td, direc, spd = np.array(arr_data).T
197
198			return dict(p=(p, unit_strs[0]), t=(t, unit_strs[2]), td=(td, unit_strs[3]),
199			wind=(direc, spd, unit_strs[7]))
200
201
202			class IAStateUpperAir(object):
203			r"""Download and parse data from the Iowa State's upper air archive."""
204			@staticmethod
205			def get_data(time, site_id):
206			r"""Download data from the Iowa State's upper air archive.
207
208			Parameters
209			----------
210			time : datetime
211			Date and time for which data should be downloaded
212			site_id : str
213			Site id for which data should be downloaded
214
215			Returns
216			-------
217			a file-like object from which to read the data
218			"""
219			url = ('http://mesonet.agron.iastate.edu/json/raob.py?ts={time:%Y%m%d%H}00'
220			'&station={stid}').format(time=time, stid=site_id)
221
222			return urlopen(url)
223
224			@staticmethod
225			def parse(fobj):
226			r"""Parse Iowa State Upper Air Data.
227
228			This parses the JSON formatted data returned by the Iowa State upper air data archive.
229
230			Parameters
231			----------
232			fobj : file-like object
233			The file-like object from which the data should be read. This needs to be set up
234			to return bytes when read, not strings.
235
236			Returns
237			-------
238			dict of information used by :func:`get_upper_air_data`
239			"""
240			json_data = json.loads(fobj.read().decode('utf-8'))['profiles'][0]['profile']
241
242			data = dict()
243			for pt in json_data:
244			for field in ('drct', 'dwpc', 'pres', 'sknt', 'tmpc'):
245			data.setdefault(field, []).append(np.nan if pt[field] is None else pt[field])
246
247			ret = dict(p=(np.array(data['pres']), 'mbar'), t=(np.array(data['tmpc']), 'degC'),
248			td=(np.array(data['dwpc']), 'degC'),
249			wind=(np.array(data['drct']), np.array(data['sknt']), 'knot'))
250
251			return ret
252

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WyomingUpperAir.to_float() A

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