Drop support for Python 2 (#2016)

Upgrade Python syntax with pyupgrade --py3-plus

dev/docker/commands.sh

@@ -30,7 +30,6 @@ export PATH=/home/travis/miniconda/bin:$PATH
 conda update --yes conda
 sudo apt-get update
 if [[ $SETUP_CMD == build_docs* ]]; then sudo apt-get install graphviz texlive-latex-extra dvipng; fi
-if [[ $TRAVIS_PYTHON_VERSION == 2.7 ]]; then export TRAVIS_PYTHON_VERSION=2.7.8; fi
 conda create --yes -n test -c astropy-ci-extras python=$TRAVIS_PYTHON_VERSION
 source activate test
 export CONDA_INSTALL="conda install -c astropy-ci-extras --yes python=$TRAVIS_PYTHON_VERSION numpy=$NUMPY_VERSION"

dev/sherpa/stats/sherpa_stats_compute_direct.py

@@ -38,5 +38,5 @@ def calc_stat(data, model, staterror):
         stat_error = stat_object.calc_staterror(0)
     except ValueError:
         stat_error = -999
-    print('%20s %20.10f' % (stat_name, stat_error))
+    print('{:>20} {:20.10f}'.format(stat_name, stat_error))
     # stat_object.calc_staterror(data=2, model=12, staterror=2)

dev/sherpa/stats/sherpa_stats_compute_via_model.py

@@ -30,4 +30,4 @@
 for stat_name in stat_names:
     set_stat(stat_name)
     stat_value = calc_stat()
-    print('%20s %20.10f' % (stat_name, stat_value))
+    print('{:>20} {:20.10f}'.format(stat_name, stat_value))

docs/astro/source/plot_snr_brightness_evolution.py

@@ -10,7 +10,7 @@
 for density in densities:
     snr = SNR(n_ISM=density)
     F = snr.luminosity_tev(t) / (4 * np.pi * Quantity(1, "kpc") ** 2)
-    plt.plot(t.value, F.to("cm-2 s-1").value, label="n_ISM = {0}".format(density.value))
+    plt.plot(t.value, F.to("cm-2 s-1").value, label="n_ISM = {}".format(density.value))
     plt.vlines(snr.sedov_taylor_begin.to("yr").value, 1e-13, 1e-10, linestyle="--")
     plt.vlines(snr.sedov_taylor_end.to("yr").value, 1e-13, 1e-10, linestyle="--")
 

docs/astro/source/plot_snr_radius_evolution.py

@@ -12,7 +12,7 @@
 for density in densities:
     for linestyle, snr_model in zip(linestyles, snr_models):
         snr = snr_model(n_ISM=density)
-        label = snr.__class__.__name__ + " (n_ISM = {0})".format(density.value)
+        label = snr.__class__.__name__ + " (n_ISM = {})".format(density.value)
         x = t.value
         y = snr.radius(t).to("pc").value
         plt.plot(x, y, label=label, linestyle=linestyle)

docs/conf.py

@@ -46,10 +46,7 @@
 from gammapy.utils.docs import gammapy_sphinx_notebooks
 
 # Get configuration information from setup.cfg
-try:
-    from ConfigParser import ConfigParser
-except ImportError:
-    from configparser import ConfigParser
+from configparser import ConfigParser
 conf = ConfigParser()
 conf.read([os.path.join(os.path.dirname(__file__), "..", "setup.cfg")])
 setup_cfg = dict(conf.items("metadata"))
@@ -112,7 +109,7 @@
 # This does not *have* to match the package name, but typically does
 project = setup_cfg["package_name"]
 author = setup_cfg["author"]
-copyright = "{0}, {1}".format(datetime.datetime.now().year, setup_cfg["author"])
+copyright = "{}, {}".format(datetime.datetime.now().year, setup_cfg["author"])
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
@@ -179,7 +176,7 @@
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
-html_title = "{0} v{1}".format(project, release)
+html_title = "{} v{}".format(project, release)
 
 # Output file base name for HTML help builder.
 htmlhelp_basename = project + "doc"
@@ -213,14 +210,14 @@ def setup(app):
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass [howto/manual]).
 latex_documents = [
-    ("index", project + ".tex", project + u" Documentation", author, "manual")
+    ("index", project + ".tex", project + " Documentation", author, "manual")
 ]
 
 # -- Options for manual page output --------------------------------------------
 
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
-man_pages = [("index", project.lower(), project + u" Documentation", [author], 1)]
+man_pages = [("index", project.lower(), project + " Documentation", [author], 1)]
 
 # -- Options for the edit_on_github extension ----------------------------------------
 

gammapy/astro/population/spatial.py

@@ -89,7 +89,7 @@ class CaseBattacharya1998(Fittable1DModel):
     evolved = True
 
     def __init__(self, amplitude=1.0, alpha=2, beta=3.53, **kwargs):
-        super(CaseBattacharya1998, self).__init__(
+        super().__init__(
             amplitude=amplitude, alpha=alpha, beta=beta, **kwargs
         )
 

gammapy/catalog/fermi.py

@@ -1019,7 +1019,7 @@ def is_source_class(self, source_class):
         elif source_class == "all":
             category = set(cats["extra-galactic"] + cats["galactic"])
         elif source_class in np.unique(source_class_info):
-            category = set([source_class])
+            category = {source_class}
         else:
             raise ValueError("Invalid source_class: {!r}".format(source_class))
 
@@ -1190,7 +1190,7 @@ def is_source_class(self, source_class):
         elif source_class == "all":
             category = set(cats["extra-galactic"] + cats["galactic"])
         elif source_class in np.unique(source_class_info):
-            category = set([source_class])
+            category = {source_class}
         else:
             raise ValueError("Invalid source_class: {!r}".format(source_class))
 

gammapy/catalog/gammacat.py

@@ -634,12 +634,12 @@ def __eq__(self, other):
     @property
     def unique_source_ids(self):
         """Sorted list of unique source IDs (list of int)."""
-        return sorted(set([resource.source_id for resource in self.resources]))
+        return sorted({resource.source_id for resource in self.resources})
 
     @property
     def unique_reference_ids(self):
         """Sorted list of unique source IDs (list of str)."""
-        return sorted(set([resource.reference_id for resource in self.resources]))
+        return sorted({resource.reference_id for resource in self.resources})
 
     @property
     def global_ids(self):

gammapy/catalog/tests/test_registry.py

@@ -39,4 +39,4 @@ def test_register(source_catalogs):
 
 def test_source_catalogs(source_catalogs):
     """Test the global registry instance"""
-    assert set(["3fgl", "2fhl"]).issubset(source_catalogs.catalog_names)
+    assert {"3fgl", "2fhl"}.issubset(source_catalogs.catalog_names)

gammapy/catalog/utils.py

@@ -142,15 +142,15 @@ def _ra_iau_format_scalar(ra, digits):
     ra_s = ra.hms[2]
 
     if digits == 2:  # format: HH
-        ra_str = "{0:02d}".format(ra_h)
+        ra_str = "{:02d}".format(ra_h)
     elif digits == 3:  # format: HHh
-        ra_str = "{0:03d}".format(int(10 * ra.hour))
+        ra_str = "{:03d}".format(int(10 * ra.hour))
     elif digits == 4:  # format: HHMM
-        ra_str = "{0:02d}{1:02d}".format(ra_h, ra_m)
+        ra_str = "{:02d}{:02d}".format(ra_h, ra_m)
     elif digits == 5:  # format : HHMM.m
-        ra_str = "{0:02d}{1:02d}.{2:01d}".format(ra_h, ra_m, int(ra_s / 6))
+        ra_str = "{:02d}{:02d}.{:01d}".format(ra_h, ra_m, int(ra_s / 6))
     elif digits == 6:  # format: HHMMSS
-        ra_str = "{0:02d}{1:02d}{2:02d}".format(ra_h, ra_m, int(ra_s))
+        ra_str = "{:02d}{:02d}{:02d}".format(ra_h, ra_m, int(ra_s))
     else:  # format: HHMMSS.s
         SS = int(ra_s)
         s_digits = digits - 6
@@ -245,13 +245,13 @@ def skycoord_from_table(table):
     except AttributeError:
         keys = table.keys()
 
-    if set(["RAJ2000", "DEJ2000"]).issubset(keys):
+    if {"RAJ2000", "DEJ2000"}.issubset(keys):
         lon, lat, frame = "RAJ2000", "DEJ2000", "icrs"
-    elif set(["RA", "DEC"]).issubset(keys):
+    elif {"RA", "DEC"}.issubset(keys):
         lon, lat, frame = "RA", "DEC", "icrs"
-    elif set(["GLON", "GLAT"]).issubset(keys):
+    elif {"GLON", "GLAT"}.issubset(keys):
         lon, lat, frame = "GLON", "GLAT", "galactic"
-    elif set(["glon", "glat"]).issubset(keys):
+    elif {"glon", "glat"}.issubset(keys):
         lon, lat, frame = "glon", "glat", "galactic"
     else:
         raise KeyError("No column GLON / GLAT or RA / DEC or RAJ2000 / DEJ2000 found.")

gammapy/detect/cwt.py

@@ -125,17 +125,17 @@ def _transform(self, data):
         """
         total_background = data._model + data._background + data._approx
         excess = data._counts - total_background
-        log.debug("Excess sum: {0:.4f}".format(excess.sum()))
-        log.debug("Excess max: {0:.4f}".format(excess.max()))
+        log.debug("Excess sum: {:.4f}".format(excess.sum()))
+        log.debug("Excess max: {:.4f}".format(excess.max()))
 
         log.debug("Computing transform and error")
         for idx_scale, kern in self.kernels.kern_base.items():
             data._transform_3d[idx_scale] = fftconvolve(excess, kern, mode="same")
             data._error[idx_scale] = np.sqrt(
                 fftconvolve(total_background, kern ** 2, mode="same")
             )
-        log.debug("Error sum: {0:.4f}".format(data._error.sum()))
-        log.debug("Error max: {0:.4f}".format(data._error.max()))
+        log.debug("Error sum: {:.4f}".format(data._error.sum()))
+        log.debug("Error max: {:.4f}".format(data._error.max()))
 
         log.debug("Computing approx and approx_bkg")
         data._approx = fftconvolve(
@@ -146,8 +146,8 @@ def _transform(self, data):
         data._approx_bkg = fftconvolve(
             data._background, self.kernels.kern_approx, mode="same"
         )
-        log.debug("Approximate sum: {0:.4f}".format(data._approx.sum()))
-        log.debug("Approximate background sum: {0:.4f}".format(data._approx_bkg.sum()))
+        log.debug("Approximate sum: {:.4f}".format(data._approx.sum()))
+        log.debug("Approximate background sum: {:.4f}".format(data._approx_bkg.sum()))
 
     def _compute_support(self, data):
         """Compute the multiresolution support with hard sigma clipping.
@@ -253,9 +253,9 @@ def _is_converged(self, data):
         log.debug("Check the convergence")
         residual = data._counts - (data._model + data._approx)
         variance = residual.var()
-        log.info("Residual sum: {0:.4f}".format(residual.sum()))
-        log.info("Residual max: {0:.4f}".format(residual.max()))
-        log.info("Residual variance: {0:.4f}".format(residual.var()))
+        log.info("Residual sum: {:.4f}".format(residual.sum()))
+        log.info("Residual max: {:.4f}".format(residual.max()))
+        log.info("Residual variance: {:.4f}".format(residual.var()))
 
         if self.previous_variance is None:
             self.previous_variance = variance

gammapy/irf/energy_dispersion.py

@@ -942,7 +942,7 @@ def plot_migration(self, ax=None, offset=None, e_true=None, migra=None, **kwargs
         for ener in e_true:
             for off in offset:
                 disp = self.data.evaluate(offset=off, e_true=ener, migra=migra)
-                label = "offset = {0:.1f}\nenergy = {1:.1f}".format(off, ener)
+                label = "offset = {:.1f}\nenergy = {:.1f}".format(off, ener)
                 ax.plot(migra, disp, label=label, **kwargs)
 
         ax.set_xlabel(r"$E_\mathrm{{Reco}} / E_\mathrm{{True}}$")

gammapy/irf/psf_3d.py

@@ -411,7 +411,7 @@ def plot_containment(
             self._plot_safe_energy_range(ax)
 
         if add_cbar:
-            label = "Containment radius R{0:.0f} ({1})" "".format(
+            label = "Containment radius R{:.0f} ({})" "".format(
                 100 * fraction, containment.unit
             )
             ax.figure.colorbar(caxes, ax=ax, label=label)
@@ -424,7 +424,7 @@ def _plot_safe_energy_range(self, ax):
         omin = self.offset.value.min()
         omax = self.offset.value.max()
         ax.hlines(y=esafe.value, xmin=omin, xmax=omax)
-        label = "Safe energy threshold: {0:3.2f}".format(esafe)
+        label = "Safe energy threshold: {:3.2f}".format(esafe)
         ax.text(x=0.1, y=0.9 * esafe.value, s=label, va="top")
 
     def peek(self, figsize=(15, 5)):

gammapy/irf/psf_gauss.py

@@ -311,7 +311,7 @@ def plot_containment(
             self._plot_safe_energy_range(ax)
 
         if add_cbar:
-            label = "Containment radius R{0:.0f} ({1})".format(
+            label = "Containment radius R{:.0f} ({})".format(
                 100 * fraction, containment.unit
             )
             ax.figure.colorbar(caxes, ax=ax, label=label)
@@ -324,7 +324,7 @@ def _plot_safe_energy_range(self, ax):
         omin = self.offset.value.min()
         omax = self.offset.value.max()
         ax.hlines(y=esafe.value, xmin=omin, xmax=omax)
-        label = "Safe energy threshold: {0:3.2f}".format(esafe)
+        label = "Safe energy threshold: {:3.2f}".format(esafe)
         ax.text(x=0.1, y=0.9 * esafe.value, s=label, va="top")
 
     def plot_containment_vs_energy(
@@ -397,17 +397,17 @@ def info(
         ss += array_stats_str(self.theta.to("deg"), "Theta")
         ss += array_stats_str(self.energy_hi, "Energy hi")
         ss += array_stats_str(self.energy_lo, "Energy lo")
-        ss += "Safe energy threshold lo: {0:6.3f}\n".format(self.energy_thresh_lo)
-        ss += "Safe energy threshold hi: {0:6.3f}\n".format(self.energy_thresh_hi)
+        ss += "Safe energy threshold lo: {:6.3f}\n".format(self.energy_thresh_lo)
+        ss += "Safe energy threshold hi: {:6.3f}\n".format(self.energy_thresh_hi)
 
         for fraction in fractions:
             containment = self.containment_radius(energies, thetas, fraction)
             for i, energy in enumerate(energies):
                 for j, theta in enumerate(thetas):
                     radius = containment[j, i]
                     ss += (
-                        "{0:2.0f}% containment radius at theta = {1} and "
-                        "E = {2:4.1f}: {3:5.8f}\n"
+                        "{:2.0f}% containment radius at theta = {} and "
+                        "E = {:4.1f}: {:5.8f}\n"
                         "".format(100 * fraction, theta, energy, radius)
                     )
         return ss

gammapy/spectrum/energy_group.py

@@ -66,7 +66,7 @@ def __init__(
 
     @classmethod
     def from_dict(cls, data):
-        data = dict((_, data[_]) for _ in cls.fields)
+        data = {_: data[_] for _ in cls.fields}
         return cls(**data)
 
     @property

gammapy/spectrum/results.py

@@ -169,7 +169,7 @@ def __str__(self):
         s += "--------------- \n"
         s += "Model: {} \n".format(self.model)
         if self.statval is not None:
-            s += "\nStatistic: {0:.3f} ({1})".format(self.statval, self.statname)
+            s += "\nStatistic: {:.3f} ({})".format(self.statval, self.statname)
         if self.fit_range is not None:
             s += "\nFit Range: {}".format(self.fit_range)
         s += "\n"

gammapy/stats/data.py

@@ -65,7 +65,7 @@ def __str__(self):
             self.background,
             self.excess,
         ]
-        return "\n".join(["%s = %s" % (k, v) for (k, v) in zip(keys, values)])
+        return "\n".join(["{} = {}".format(k, v) for (k, v) in zip(keys, values)])
 
 
 def make_stats(

gammapy/stats/tests/test_feldman_cousins.py

@@ -123,9 +123,9 @@ def test_numerical_confidence_interval_values():
     x_bins = np.linspace(-n_sigma * sigma, n_sigma * sigma, n_bins_x, endpoint=True)
     mu_bins = np.linspace(mu_min, mu_max, mu_max / step_width_mu + 1, endpoint=True)
 
-    distribution_dict = dict(
-        (mu, [scipy.stats.norm.rvs(loc=mu, scale=sigma, size=5000)]) for mu in mu_bins
-    )
+    distribution_dict = {
+        mu: [scipy.stats.norm.rvs(loc=mu, scale=sigma, size=5000)] for mu in mu_bins
+    }
 
     acceptance_intervals = fc_construct_acceptance_intervals(
         distribution_dict, x_bins, cl

gammapy/time/lightcurve.py

@@ -225,7 +225,7 @@ def plot(self, ax=None, time_format="mjd", flux_unit="cm-2 s-1", **kwargs):
 
         ax.errorbar(x=x, y=y, xerr=xerr, yerr=yerr, uplims=is_ul, **kwargs)
         ax.set_xlabel("Time ({})".format(time_format.upper()))
-        ax.set_ylabel("Flux ({0:FITS})".format(u.Unit(flux_unit)))
+        ax.set_ylabel("Flux ({:FITS})".format(u.Unit(flux_unit)))
         if time_format == "iso":
             ax.xaxis.set_major_formatter(DateFormatter("%Y-%m-%d %H:%M:%S"))
             plt.setp(

gammapy/utils/array.py

@@ -29,7 +29,7 @@ def array_stats_str(x, label=""):
 
     ss = ""
     if label:
-        ss += "{0:15s}: ".format(label)
+        ss += "{:15s}: ".format(label)
 
     min = x.min()
     max = x.max()

gammapy/utils/energy.py

@@ -251,7 +251,7 @@ def equal_log_spacing(cls, emin, emax, nbins, unit=None):
         unit : `~astropy.units.UnitBase`, str, None
             Energy unit
         """
-        return super(EnergyBounds, cls).equal_log_spacing(emin, emax, nbins + 1, unit)
+        return super().equal_log_spacing(emin, emax, nbins + 1, unit)
 
     @classmethod
     def from_ebounds(cls, hdu):

gammapy/utils/testing.py

@@ -174,7 +174,7 @@ def _unquantify_allclose_arguments(actual, desired, rtol, atol):
         desired = desired.to(actual.unit)
     except u.UnitsError:
         raise u.UnitsError(
-            "Units for 'desired' ({0}) and 'actual' ({1}) "
+            "Units for 'desired' ({}) and 'actual' ({}) "
             "are not convertible".format(desired.unit, actual.unit)
         )
 
@@ -187,7 +187,7 @@ def _unquantify_allclose_arguments(actual, desired, rtol, atol):
             atol = atol.to(actual.unit)
         except u.UnitsError:
             raise u.UnitsError(
-                "Units for 'atol' ({0}) and 'actual' ({1}) "
+                "Units for 'atol' ({}) and 'actual' ({}) "
                 "are not convertible".format(atol.unit, actual.unit)
             )