Merge pull request #1841 from dopplershift/drop36

Drop support for Python 3.6

.github/workflows/docs-conda.yml

@@ -7,7 +7,7 @@ on:
 
 jobs:
   #
-  # Build our docs on macOS and Windows on Python 3.6 and 3.7, respectively.
+  # Build our docs on macOS and Windows on Python 3.8 and 3.7, respectively.
   #
   Docs:
     name: ${{ matrix.os }} ${{ matrix.python-version }}
@@ -19,7 +19,7 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - python-version: 3.6
+          - python-version: 3.8
             os: macOS
           - python-version: 3.7
             os: Windows
@@ -55,11 +55,6 @@ jobs:
         # Needed for caching
         use-only-tar-bz2: true
 
-    # TODO: Remove this when we drop Python 3.6
-    - name: Adjust traitlets dependency for Python 3.6
-      if: ${{ matrix.python-version == 3.6 }}
-      run: sed -e "s/traitlets==.*/traitlets==4.3.3/" -i.bak ci/requirements.txt
-
     # TODO: Remove this when scipy>1.5.3 is available on conda-forge
     - name: Adjust scipy dependency for Conda
       run: sed -e "s/scipy==.*/scipy==1.5.3/" -i.bak ci/requirements.txt

.github/workflows/tests-pypi.yml

@@ -18,11 +18,11 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: [3.7, 3.8, 3.9]
         dep-versions: [requirements.txt]
         no-extras: ['']
         include:
-          - python-version: 3.6
+          - python-version: 3.7
             dep-versions: Minimum
             no-extras: ''
           - python-version: 3.9
@@ -63,11 +63,6 @@ jobs:
           pip-tests-${{ runner.os }}-
           pip-tests-
 
-    # TODO: Remove this when we drop Python 3.6
-    - name: Adjust traitlets dependency for Python 3.6
-      if: ${{ matrix.python-version == 3.6 }}
-      run: sed -e "s/traitlets==.*/traitlets==4.3.3/" -i.bak ci/requirements.txt
-
     - name: Add extras to requirements
       if: ${{ matrix.no-extras != 'No Extras' }}
       run: cat ci/extra_requirements.txt >> ci/test_requirements.txt

README.md

@@ -30,11 +30,7 @@ on a future ``1.x`` version.
 For additional MetPy examples not included in this repository, please see the [Unidata Python
 Gallery](https://unidata.github.io/python-gallery/).
 
-We support Python >= 3.6.
-
-0.12 is the first version to drop support for Python 2.7 in Fall 2019. See
-[here](https://github.com/Unidata/MetPy/blob/main/docs/installguide.rst) for more
-information.
+We support Python >= 3.7.
 
 Need Help?
 ----------

ci/Minimum

@@ -1,11 +1,11 @@
 importlib_metadata==1.0.0
 importlib_resources==1.3.0
-matplotlib==2.1.0
+matplotlib==3.0.1
 numpy==1.16.0
 pandas==0.24.0
 pint==0.10.1
 pooch==0.1
 pyproj==2.3.0
-scipy==1.0.0
+scipy==1.2.0
 traitlets==4.3.0
 xarray==0.14.1

docs/conf.py

@@ -11,6 +11,7 @@
 
 from datetime import datetime
 import os
+from pathlib import Path
 import re
 import sys
 
@@ -19,9 +20,10 @@
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
-# documentation root, use os.path.abspath to make it absolute, like shown here.
-sys.path.insert(0, os.path.abspath('.'))
-sys.path.insert(0, os.path.abspath(os.path.join('..', '..')))
+# documentation root, use resolve() to make it absolute, like shown here.
+cwd = Path.cwd().resolve()
+sys.path.insert(0, str(cwd))
+sys.path.insert(0, str(cwd.parent.parent))
 
 # -- General configuration ------------------------------------------------
 
@@ -49,11 +51,11 @@
     'reference_url': {
         'metpy': None,
     },
-    'examples_dirs': [os.path.join('..', 'examples'), os.path.join('..', 'tutorials')],
+    'examples_dirs': [str(cwd.parent / 'examples'), str(cwd.parent / 'tutorials')],
     'gallery_dirs': ['examples', 'tutorials'],
     'filename_pattern': r'\.py',
-    'backreferences_dir': os.path.join('api', 'generated'),
-    'default_thumb_file': os.path.join('_static', 'metpy_150x150_white_bg.png'),
+    'backreferences_dir': str(Path('api') / 'generated'),
+    'default_thumb_file': str(Path('_static') / 'metpy_150x150_white_bg.png'),
     'abort_on_example_error': True
 }
 
@@ -208,12 +210,12 @@
 
 # The name of an image file (relative to this directory) to place at the top
 # of the sidebar.
-html_logo = os.path.join('_static', 'metpy_horizontal.png')
+html_logo = str(Path('_static') / 'metpy_horizontal.png')
 
 # The name of an image file (within the static path) to use as favicon of the
 # docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
 # pixels large.
-html_favicon = os.path.join('_static', 'metpy_32x32.ico')
+html_favicon = str(Path('_static') / 'metpy_32x32.ico')
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,

docs/index.rst

@@ -14,7 +14,7 @@ MetPy
 =====
 
 MetPy is a collection of tools in Python for reading, visualizing, and performing calculations
-with weather data. MetPy supports Python >= 3.6 and is freely available under a permissive
+with weather data. MetPy supports Python >= 3.7 and is freely available under a permissive
 `open source license <https://github.com/Unidata/MetPy/blob/main/LICENSE>`_.
 
 If you're new to MetPy, check out our :doc:`Getting Started <userguide/startingguide>` guide.

docs/override_check.py

@@ -4,21 +4,18 @@
 #
 # Verifies that any modules present in the _templates/overrides directory have all of their
 # their exported functions included in the doc file.
-import glob
 import importlib
-import os
+from pathlib import Path
 import sys
 
 
 modules_to_skip = ['metpy.xarray']
 
 
 failed = False
-for full_path in glob.glob('_templates/overrides/metpy.*.rst'):
-
-    filename = os.path.basename(full_path)
-    module = filename.split('.rst')[0]
+for full_path in (Path('_templates') / 'overrides').glob('metpy.*.rst'):
 
+    module = full_path.with_suffix('').name
     if module in modules_to_skip:
         continue
 
@@ -37,7 +34,7 @@
     if missing_functions:
         failed = True
         print('ERROR - The following functions are missing from the override file ' +
-              filename + ': ' + ', '.join(missing_functions), file=sys.stderr)
+              str(full_path.name) + ': ' + ', '.join(missing_functions), file=sys.stderr)
 
 # Report status
 if failed:

docs/userguide/installguide.rst

@@ -7,15 +7,15 @@ Requirements
 ------------
 In general, MetPy tries to support minor versions of dependencies released within the last two
 years. For Python itself, that generally means supporting the last two minor releases; MetPy
-currently supports Python >= 3.6.
+currently supports Python >= 3.7.
 
-* matplotlib >= 2.1.0
+* matplotlib >= 3.0.1
 * numpy >= 1.16.0
 * pandas >= 0.24.0
 * pint >= 0.10.1
 * pooch >= 0.1
 * pyproj >= 2.3.0
-* scipy >= 1.0.0
+* scipy >= 1.2.0
 * traitlets >= 4.3.0
 * xarray >= 0.14.1
 

examples/cross_section.py

@@ -120,11 +120,10 @@
 
 # Set the titles and axes labels
 ax_inset.set_title('')
-ax.set_title('NARR Cross-Section \u2013 {} to {} \u2013 Valid: {}\n'
-             'Potential Temperature (K), Tangential/Normal Winds (knots), '
-             'Relative Humidity (dimensionless)\n'
-             'Inset: Cross-Section Path and 500 hPa Geopotential Height'.format(
-                 start, end, cross['time'].dt.strftime('%Y-%m-%d %H:%MZ').item()))
+ax.set_title(f'NARR Cross-Section \u2013 {start} to {end} \u2013 '
+             f'Valid: {cross["time"].dt.strftime("%Y-%m-%d %H:%MZ").item()}\n'
+             'Potential Temperature (K), Tangential/Normal Winds (knots), Relative Humidity '
+             '(dimensionless)\nInset: Cross-Section Path and 500 hPa Geopotential Height')
 ax.set_ylabel('Pressure (hPa)')
 ax.set_xlabel('Longitude (degrees east)')
 rh_colorbar.set_label('Relative Humidity (dimensionless)')

setup.cfg

@@ -15,7 +15,6 @@ classifiers =
     Development Status :: 5 - Production/Stable
     Framework :: Matplotlib
     Programming Language :: Python
-    Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
@@ -38,7 +37,7 @@ package_dir =
 packages = find:
 include_package_data = True
 setup_requires = setuptools_scm
-python_requires = >=3.6
+python_requires = >=3.7
 install_requires =
     importlib_metadata>=1.0.0; python_version < '3.8'
     importlib_resources>=1.3.0; python_version < '3.9'
@@ -81,11 +80,10 @@ rst-roles = class, data, doc, func, meth, mod
 rst-directives = plot, versionchanged
 docstring-convention = numpy
 exclude = docs build src/metpy/io/metar_parser.py
-select = A B C D E F H I M Q RST S T W B902
+select = A B C D E F G H I J K L M N O P Q R S T U V W X Y Z B902
 ignore = F405 W503 RST902 SIM106
 per-file-ignores = examples/*.py: D MPY001 T003 T001
                    tutorials/*.py: D MPY001 T003 T001
-                   src/metpy/xarray.py: RST304
                    src/metpy/deprecation.py: C801
                    src/metpy/calc/*.py: RST306
                    src/metpy/interpolate/*.py: RST306

setup.py

@@ -9,7 +9,7 @@
 
 if sys.version_info[0] < 3:
     error = """
-    MetPy v0.12 and greater requires the Python 3.6 or above.
+    MetPy v1.1 and greater requires Python 3.7 or above.
     If you're using Python 2.7, please install MetPy v0.11.1,
     which is the last release of MetPy that supports Python 2.7,
     but it is no longer maintained.

src/metpy/calc/thermo.py

@@ -3238,11 +3238,11 @@ def lifted_index(pressure, temperature, parcel_profile):
     # find the index for the 500 hPa pressure level.
     idx = np.where(pressure == units.Quantity(500, 'hPa'))
     # find the measured temperature at 500 hPa.
-    T500 = temperature[idx]
+    t500 = temperature[idx]
     # find the parcel profile temperature at 500 hPa.
-    Tp500 = parcel_profile[idx]
+    tp500 = parcel_profile[idx]
     # calculate the lifted index.
-    lifted_index = T500 - Tp500.to(units.degC)
+    lifted_index = t500 - tp500.to(units.degC)
     return lifted_index
 
 

src/metpy/io/_tools.py

@@ -264,7 +264,7 @@ def read_binary(self, num, item_type='B'):
         else:
             order = '@'
 
-        return list(self.read_struct(Struct(order + '{:d}'.format(int(num)) + item_type)))
+        return list(self.read_struct(Struct(order + f'{int(num):d}' + item_type)))
 
     def read_int(self, size, endian, signed):
         """Parse the current buffer offset as the specified integer code."""
@@ -314,7 +314,7 @@ def __getitem__(self, item):
 
     def __str__(self):
         """Return a string representation of the IOBuffer."""
-        return 'Size: {} Offset: {}'.format(len(self._data), self._offset)
+        return f'Size: {len(self._data)} Offset: {self._offset}'
 
     def __len__(self):
         """Return the amount of data in the buffer."""

src/metpy/io/nexrad.py

@@ -452,7 +452,7 @@ def _decode_msg5(self, msg_hdr):
     def _decode_msg13(self, msg_hdr):
         data = self._buffer_segment(msg_hdr)
         if data:
-            data = Struct('>{:d}h'.format(len(data) // 2)).unpack(data)
+            data = Struct(f'>{len(data) // 2:d}h').unpack(data)
             # Legacy format doesn't have date/time and has fewer azimuths
             if data[0] <= 5:
                 num_el = data[0]
@@ -495,7 +495,7 @@ def _decode_msg15(self, msg_hdr):
         # will be returned concatenated when this is the case
         data = self._buffer_segment(msg_hdr)
         if data:
-            date, time, num_el, *data = Struct('>{:d}h'.format(len(data) // 2)).unpack(data)
+            date, time, num_el, *data = Struct(f'>{len(data) // 2:d}h').unpack(data)
             if num_el == 0:
                 log.info('Message 15 num_el is 0--likely legacy clutter filter notch width. '
                          'Skipping...')

src/metpy/plots/ctables.py

@@ -39,9 +39,8 @@ def plot_color_gradients(cmap_category, cmap_list, nrows):
 """
 
 import ast
-import glob
 import logging
-import os.path
+from pathlib import Path
 
 import matplotlib.colors as mcolors
 
@@ -112,7 +111,7 @@ def convert_gempak_table(infile, outfile):
     for line in infile:
         if not line.startswith('!') and line.strip():
             r, g, b = map(int, line.split())
-            outfile.write('({:f}, {:f}, {:f})\n'.format(r / 255, g / 255, b / 255))
+            outfile.write(f'({r / 255:f}, {g / 255:f}, {b / 255:f})\n')
 
 
 class ColortableRegistry(dict):
@@ -152,15 +151,15 @@ def scan_dir(self, path):
             The path to the directory with the color tables
 
         """
-        for fname in glob.glob(os.path.join(path, '*' + TABLE_EXT)):
-            if os.path.isfile(fname):
-                with open(fname) as fobj:
+        for entry in Path(path).glob('*' + TABLE_EXT):
+            if entry.is_file():
+                with entry.open() as fobj:
                     try:
-                        self.add_colortable(fobj, os.path.splitext(os.path.basename(fname))[0])
-                        log.debug('Added colortable from file: %s', fname)
+                        self.add_colortable(fobj, entry.with_suffix('').name)
+                        log.debug('Added colortable from file: %s', entry)
                     except RuntimeError:
                         # If we get a file we can't handle, assume we weren't meant to.
-                        log.info('Skipping unparsable file: %s', fname)
+                        log.info('Skipping unparsable file: %s', entry)
 
     def add_colortable(self, fobj, name):
         r"""Add a color table from a file to the registry.
@@ -274,7 +273,7 @@ def get_colortable(self, name):
 
 registry = ColortableRegistry()
 registry.scan_resource('metpy.plots', 'colortable_files')
-registry.scan_dir(os.path.curdir)
+registry.scan_dir(Path.cwd())
 
 with exporter:
     colortables = registry

tests/calc/test_indices.py

@@ -76,11 +76,11 @@ def test_mean_pressure_weighted():
 def test_mean_pressure_weighted_temperature():
     """Test pressure-weighted mean temperature function with vertical interpolation."""
     data = get_upper_air_data(datetime(2016, 5, 22, 0), 'DDC')
-    T, = mean_pressure_weighted(data['pressure'],
+    t, = mean_pressure_weighted(data['pressure'],
                                 data['temperature'],
                                 height=data['height'],
                                 depth=6000 * units('meter'))
-    assert_almost_equal(T, 281.535035296836 * units('kelvin'), 7)
+    assert_almost_equal(t, 281.535035296836 * units('kelvin'), 7)
 
 
 def test_mean_pressure_weighted_elevated():

tests/calc/test_thermo.py

@@ -1830,7 +1830,7 @@ def test_cape_cin_value_error():
     assert_almost_equal(cin, expected_cin, 3)
 
 
-def test_lcl_grid_surface_LCLs():
+def test_lcl_grid_surface_lcls():
     """Test surface grid where some values have LCLs at the surface."""
     pressure = np.array([1000, 990, 1010]) * units.hPa
     temperature = np.array([15, 14, 13]) * units.degC
@@ -1863,8 +1863,8 @@ def test_lifted_index():
                          -34.1, -37.3, -32.3, -34.1, -37.3, -41.1, -37.7, -58.1,
                          -57.5]) * units.degC
     parcel_prof = parcel_profile(pressure, temperature[0], dewpoint[0])
-    LI = lifted_index(pressure, temperature, parcel_prof)
-    assert_almost_equal(LI, -7.9176350 * units.delta_degree_Celsius, 2)
+    li = lifted_index(pressure, temperature, parcel_prof)
+    assert_almost_equal(li, -7.9176350 * units.delta_degree_Celsius, 2)
 
 
 def test_gradient_richardson_number():