Removed Python2 support

Closes: #6890

Some remarks,

- `# coding ... utf-8` statements are not needed
- isdigit on strings instead of a try-catch.
- Default opening mode is read, so we can do `open()` without the `'r'` everywhere
- Removed inheritinng from `object` class, it isn't necessary in python3.
- `super(ClassName, self)` can now be replaced with `super()`
- Use of itertools and `chain` on a couple places dealing with sets.
- Used the operator module instead of lambdas when warranted
    `itemgetter(0)` instead of `lambda x: x[0]`
    `attrgetter('name')` instead of `lambda x: x.name`
- `sorted` returns a list, so no need to use `list(sorted(...))`
- Removed `dict()` using dictionary comprehensions whenever possible
- Attempted to remove python3.2 support

Signed-off-by: alexrecuenco <alejandrogonzalezrecuenco@gmail.com>

.pre-commit-config.yaml

@@ -20,3 +20,9 @@
       language_version: 'python3.7'
       args:
          - --py3-plus
+-   repo: https://github.com/asottile/pyupgrade
+    rev: v2.1.0
+    hooks:
+    -   id: pyupgrade
+        args:
+          - --py3-plus

compose/cli/colors.py

@@ -14,16 +14,16 @@
 
 def get_pairs():
     for i, name in enumerate(NAMES):
-        yield(name, str(30 + i))
-        yield('intense_' + name, str(30 + i) + ';1')
+        yield (name, str(30 + i))
+        yield ('intense_' + name, str(30 + i) + ';1')
 
 
 def ansi(code):
-    return '\033[{0}m'.format(code)
+    return '\033[{}m'.format(code)
 
 
 def ansi_color(code, s):
-    return '{0}{1}{2}'.format(ansi(code), s, ansi(0))
+    return '{}{}{}'.format(ansi(code), s, ansi(0))
 
 
 def make_color_fn(code):

compose/cli/command.py

@@ -149,15 +149,17 @@ def get_project(project_dir, config_path=None, project_name=None, verbose=False,
 
 def execution_context_labels(config_details, environment_file):
     extra_labels = [
-        '{0}={1}'.format(LABEL_WORKING_DIR, os.path.abspath(config_details.working_dir))
+        '{}={}'.format(LABEL_WORKING_DIR, os.path.abspath(config_details.working_dir))
     ]
 
     if not use_config_from_stdin(config_details):
-        extra_labels.append('{0}={1}'.format(LABEL_CONFIG_FILES, config_files_label(config_details)))
+        extra_labels.append('{}={}'.format(LABEL_CONFIG_FILES, config_files_label(config_details)))
 
     if environment_file is not None:
-        extra_labels.append('{0}={1}'.format(LABEL_ENVIRONMENT_FILE,
-                                             os.path.normpath(environment_file)))
+        extra_labels.append('{}={}'.format(
+            LABEL_ENVIRONMENT_FILE,
+            os.path.normpath(environment_file))
+            )
     return extra_labels
 
 
@@ -170,7 +172,8 @@ def use_config_from_stdin(config_details):
 
 def config_files_label(config_details):
     return ",".join(
-        map(str, (os.path.normpath(c.filename) for c in config_details.config_files)))
+        os.path.normpath(c.filename) for c in config_details.config_files
+        )
 
 
 def get_project_name(working_dir, project_name=None, environment=None):

compose/cli/docopt_command.py

@@ -11,7 +11,7 @@ def docopt_full_help(docstring, *args, **kwargs):
         raise SystemExit(docstring)
 
 
-class DocoptDispatcher(object):
+class DocoptDispatcher:
 
     def __init__(self, command_class, options):
         self.command_class = command_class
@@ -50,7 +50,7 @@ def get_handler(command_class, command):
 
 class NoSuchCommand(Exception):
     def __init__(self, command, supercommand):
-        super(NoSuchCommand, self).__init__("No such command: %s" % command)
+        super().__init__("No such command: %s" % command)
 
         self.command = command
         self.supercommand = supercommand

compose/cli/errors.py

@@ -26,11 +26,9 @@ class UserError(Exception):
     def __init__(self, msg):
         self.msg = dedent(msg).strip()
 
-    def __unicode__(self):
+    def __str__(self):
         return self.msg
 
-    __str__ = __unicode__
-
 
 class ConnectionError(Exception):
     pass

compose/cli/formatter.py

@@ -1,15 +1,10 @@
 import logging
-import shutil
+from shutil import get_terminal_size
 
 import texttable
 
 from compose.cli import colors
 
-if hasattr(shutil, "get_terminal_size"):
-    from shutil import get_terminal_size
-else:
-    from backports.shutil_get_terminal_size import get_terminal_size
-
 
 def get_tty_width():
     try:
@@ -45,15 +40,15 @@ class ConsoleWarningFormatter(logging.Formatter):
 
     def get_level_message(self, record):
         separator = ': '
-        if record.levelno == logging.WARNING:
-            return colors.yellow(record.levelname) + separator
-        if record.levelno == logging.ERROR:
+        if record.levelno >= logging.ERROR:
             return colors.red(record.levelname) + separator
+        if record.levelno >= logging.WARNING:
+            return colors.yellow(record.levelname) + separator
 
         return ''
 
     def format(self, record):
         if isinstance(record.msg, bytes):
             record.msg = record.msg.decode('utf-8')
-        message = super(ConsoleWarningFormatter, self).format(record)
-        return '{0}{1}'.format(self.get_level_message(record), message)
+        message = super().format(record)
+        return '{}{}'.format(self.get_level_message(record), message)

compose/cli/log_printer.py

@@ -2,6 +2,7 @@
 import sys
 from collections import namedtuple
 from itertools import cycle
+from operator import attrgetter
 from queue import Empty
 from queue import Queue
 from threading import Thread
@@ -13,7 +14,7 @@
 from compose.utils import split_buffer
 
 
-class LogPresenter(object):
+class LogPresenter:
 
     def __init__(self, prefix_width, color_func):
         self.prefix_width = prefix_width
@@ -50,7 +51,7 @@ def max_name_width(service_names, max_index_width=3):
     return max(len(name) for name in service_names) + max_index_width
 
 
-class LogPrinter(object):
+class LogPrinter:
     """Print logs from many containers to a single output stream."""
 
     def __init__(self,
@@ -133,7 +134,7 @@ def build_thread_map(initial_containers, presenters, thread_args):
         # Container order is unspecified, so they are sorted by name in order to make
         # container:presenter (log color) assignment deterministic when given a list of containers
         # with the same names.
-        for container in sorted(initial_containers, key=lambda c: c.name)
+        for container in sorted(initial_containers, key=attrgetter('name'))
     }
 
 
@@ -194,9 +195,9 @@ def build_log_generator(container, log_args):
 def wait_on_exit(container):
     try:
         exit_code = container.wait()
-        return "%s exited with code %s\n" % (container.name, exit_code)
+        return "{} exited with code {}\n".format(container.name, exit_code)
     except APIError as e:
-        return "Unexpected API error for %s (HTTP code %s)\nResponse body:\n%s\n" % (
+        return "Unexpected API error for {} (HTTP code {})\nResponse body:\n{}\n".format(
             container.name, e.response.status_code,
             e.response.text or '[empty]'
         )

compose/cli/main.py

@@ -74,7 +74,7 @@ def main():
         log.error(e.msg)
         sys.exit(1)
     except BuildError as e:
-        log.error("Service '%s' failed to build: %s" % (e.service.name, e.reason))
+        log.error("Service '{}' failed to build: {}".format(e.service.name, e.reason))
         sys.exit(1)
     except StreamOutputError as e:
         log.error(e)
@@ -176,7 +176,7 @@ def parse_doc_section(name, source):
     return [s.strip() for s in pattern.findall(source)]
 
 
-class TopLevelCommand(object):
+class TopLevelCommand:
     """Define and run multi-container applications with Docker.
 
     Usage:
@@ -547,7 +547,7 @@ def images(self, options):
             key=attrgetter('name'))
 
         if options['--quiet']:
-            for image in set(c.image for c in containers):
+            for image in {c.image for c in containers}:
                 print(image.split(':')[1])
             return
 
@@ -1137,7 +1137,7 @@ def compute_service_exit_code(exit_value_from, attached_containers):
         attached_containers))
     if not candidates:
         log.error(
-            'No containers matching the spec "{0}" '
+            'No containers matching the spec "{}" '
             'were run.'.format(exit_value_from)
         )
         return 2
@@ -1463,10 +1463,7 @@ def call_docker(args, dockeropts, environment):
     args = [executable_path] + tls_options + args
     log.debug(" ".join(map(pipes.quote, args)))
 
-    filtered_env = {}
-    for k, v in environment.items():
-        if v is not None:
-            filtered_env[k] = environment[k]
+    filtered_env = {k: v for k, v in environment.items() if v is not None}
 
     return subprocess.call(args, env=filtered_env)
 

compose/cli/utils.py

@@ -11,13 +11,6 @@
 import compose
 from ..const import IS_WINDOWS_PLATFORM
 
-# WindowsError is not defined on non-win32 platforms. Avoid runtime errors by
-# defining it as OSError (its parent class) if missing.
-try:
-    WindowsError
-except NameError:
-    WindowsError = OSError
-
 
 def yesno(prompt, default=None):
     """
@@ -58,7 +51,7 @@ def call_silently(*args, **kwargs):
     with open(os.devnull, 'w') as shutup:
         try:
             return subprocess.call(*args, stdout=shutup, stderr=shutup, **kwargs)
-        except WindowsError:
+        except OSError:
             # On Windows, subprocess.call() can still raise exceptions. Normalize
             # to POSIXy behaviour by returning a nonzero exit code.
             return 1
@@ -120,7 +113,7 @@ def generate_user_agent():
     try:
         p_system = platform.system()
         p_release = platform.release()
-    except IOError:
+    except OSError:
         pass
     else:
         parts.append("{}/{}".format(p_system, p_release))
@@ -133,7 +126,7 @@ def human_readable_file_size(size):
     if order >= len(suffixes):
         order = len(suffixes) - 1
 
-    return '{0:.4g} {1}'.format(
+    return '{:.4g} {}'.format(
         size / pow(10, order * 3),
         suffixes[order]
     )

compose/cli/verbose_proxy.py

@@ -6,13 +6,13 @@
 
 def format_call(args, kwargs):
     args = (repr(a) for a in args)
-    kwargs = ("{0!s}={1!r}".format(*item) for item in kwargs.items())
-    return "({0})".format(", ".join(chain(args, kwargs)))
+    kwargs = ("{!s}={!r}".format(*item) for item in kwargs.items())
+    return "({})".format(", ".join(chain(args, kwargs)))
 
 
 def format_return(result, max_lines):
     if isinstance(result, (list, tuple, set)):
-        return "({0} with {1} items)".format(type(result).__name__, len(result))
+        return "({} with {} items)".format(type(result).__name__, len(result))
 
     if result:
         lines = pprint.pformat(result).split('\n')
@@ -22,7 +22,7 @@ def format_return(result, max_lines):
     return result
 
 
-class VerboseProxy(object):
+class VerboseProxy:
     """Proxy all function calls to another class and log method name, arguments
     and return values for each call.
     """