Adds pre-commit config to run various lintersci_improvements

This ads black, isort, pyupgrade, and flake8 to pre-commit-config.yaml
There are also some small changes to travis.yml and tasks.py to reduce
some repeated configurations that should be consolidated into
setup.cfg. Most other changes are automated by the linter scripts.

1 files changed, 30 insertions, 25 deletions

diff --git a/cmd2/parsing.py b/cmd2/parsing.py
index c420e9aa..486cd7ed 100755
--- a/cmd2/parsing.py
+++ b/cmd2/parsing.py
@@ -30,6 +30,7 @@ class MacroArg:
     Normal argument syntax:    {5}
     Escaped argument syntax:  {{5}}
     """
+
     # The starting index of this argument in the macro value
     start_index = attr.ib(validator=attr.validators.instance_of(int))
 
@@ -102,6 +103,7 @@ class Statement(str):
     3. If you don't want to have to worry about quoted arguments, see
        :attr:`argv` for a trick which strips quotes off for you.
     """
+
     # the arguments, but not the command, nor the output redirection clauses.
     args = attr.ib(default='', validator=attr.validators.instance_of(str))
 
@@ -209,11 +211,14 @@ class Statement(str):
 
 class StatementParser:
     """Parse user input as a string into discrete command components."""
-    def __init__(self,
-                 terminators: Optional[Iterable[str]] = None,
-                 multiline_commands: Optional[Iterable[str]] = None,
-                 aliases: Optional[Dict[str, str]] = None,
-                 shortcuts: Optional[Dict[str, str]] = None) -> None:
+
+    def __init__(
+        self,
+        terminators: Optional[Iterable[str]] = None,
+        multiline_commands: Optional[Iterable[str]] = None,
+        aliases: Optional[Dict[str, str]] = None,
+        shortcuts: Optional[Dict[str, str]] = None,
+    ) -> None:
         """Initialize an instance of StatementParser.
 
         The following will get converted to an immutable tuple before storing internally:
@@ -406,7 +411,7 @@ class StatementParser:
             arg_list = tokens[1:terminator_pos]
             # we will set the suffix later
             # remove all the tokens before and including the terminator
-            tokens = tokens[terminator_pos + 1:]
+            tokens = tokens[terminator_pos + 1 :]
         else:
             (testcommand, testargs) = self._command_and_args(tokens)
             if testcommand in self.multiline_commands:
@@ -442,7 +447,7 @@ class StatementParser:
         if pipe_index < redir_index and pipe_index < append_index:
 
             # Get the tokens for the pipe command and expand ~ where needed
-            pipe_to_tokens = tokens[pipe_index + 1:]
+            pipe_to_tokens = tokens[pipe_index + 1 :]
             utils.expand_user_in_tokens(pipe_to_tokens)
 
             # Build the pipe command line string
@@ -487,16 +492,18 @@ class StatementParser:
             multiline_command = ''
 
         # build the statement
-        statement = Statement(args,
-                              raw=line,
-                              command=command,
-                              arg_list=arg_list,
-                              multiline_command=multiline_command,
-                              terminator=terminator,
-                              suffix=suffix,
-                              pipe_to=pipe_to,
-                              output=output,
-                              output_to=output_to)
+        statement = Statement(
+            args,
+            raw=line,
+            command=command,
+            arg_list=arg_list,
+            multiline_command=multiline_command,
+            terminator=terminator,
+            suffix=suffix,
+            pipe_to=pipe_to,
+            output=output,
+            output_to=output_to,
+        )
         return statement
 
     def parse_command_only(self, rawinput: str) -> Statement:
@@ -538,7 +545,7 @@ class StatementParser:
             # take everything from the end of the first match group to
             # the end of the line as the arguments (stripping leading
             # and trailing spaces)
-            args = line[match.end(1):].strip()
+            args = line[match.end(1) :].strip()
             # if the command is empty that means the input was either empty
             # or something weird like '>'. args should be empty if we couldn't
             # parse a command
@@ -552,14 +559,12 @@ class StatementParser:
             multiline_command = ''
 
         # build the statement
-        statement = Statement(args,
-                              raw=rawinput,
-                              command=command,
-                              multiline_command=multiline_command)
+        statement = Statement(args, raw=rawinput, command=command, multiline_command=multiline_command)
         return statement
 
-    def get_command_arg_list(self, command_name: str, to_parse: Union[Statement, str],
-                             preserve_quotes: bool) -> Tuple[Statement, List[str]]:
+    def get_command_arg_list(
+        self, command_name: str, to_parse: Union[Statement, str], preserve_quotes: bool
+    ) -> Tuple[Statement, List[str]]:
         """
         Convenience method used by the argument parsing decorators.
 
@@ -610,7 +615,7 @@ class StatementParser:
                 # Check if this command matches an alias that wasn't already processed
                 if command in remaining_aliases:
                     # rebuild line with the expanded alias
-                    line = self.aliases[command] + match.group(2) + line[match.end(2):]
+                    line = self.aliases[command] + match.group(2) + line[match.end(2) :]
                     remaining_aliases.remove(command)
                     keep_expanding = bool(remaining_aliases)