Fix most unused variable errors.

Get rid of pep8 functions, because flake8 is a superset of pep8.

core/braces.py

@@ -221,7 +221,6 @@ def _BraceExpand(parts):
    return [parts]

  elif num_alts == 1:
    out = []
    suffix = parts[first_alt_index+1 : ]
    return _BraceExpandOne(parts, first_alt_index, [suffix])

core/builtin.py

@@ -495,7 +495,7 @@ def Shift(argv, mem):
    n = int(argv[0])
  except IndexError:
    n = 1
  except ValueError as e:
  except ValueError:
    print("Invalid shift argument %r" % argv[1], file=sys.stderr)
    return 1  # runtime error

@@ -655,7 +655,7 @@ def Export(argv, mem):
        raise args.UsageError('export: Invalid variable name %r' % name)

      # NOTE: bash doesn't care if it wasn't found.
      _ = mem.ClearFlag(name, var_flags_e.Exported, scope_e.Dynamic)
      mem.ClearFlag(name, var_flags_e.Exported, scope_e.Dynamic)
  else:
    for arg in argv[i:]:
      parts = arg.split('=', 1)

core/cmd_exec.py

@@ -267,8 +267,6 @@ def _Exec(self, argv):
      return 0

  def _RunBuiltin(self, builtin_id, argv):
    restore_fd_state = True

    # NOTE: Builtins don't need to know their own name.
    argv = argv[1:]

@@ -634,7 +632,6 @@ def _SetSourceLocation(self, span_id):
    # TODO: This API should be simplified
    line_span = self.arena.GetLineSpan(span_id)
    line_id = line_span.line_id
    line = self.arena.GetLine(line_id)
    source_name, line_num = self.arena.GetDebugInfo(line_id)
    self.mem.SetSourceLocation(source_name, line_num)

@@ -650,7 +647,7 @@ def _Dispatch(self, node, fork_external):
    # command.
    self.check_command_sub_status = False

    argv0 = None  # for error message
    #argv0 = None  # for error message
    check_errexit = False  # for errexit

    if node.tag == command_e.SimpleCommand:
@@ -759,7 +756,6 @@ def _Dispatch(self, node, fork_external):
      status = 0 if i != 0 else 1

    elif node.tag == command_e.Assignment:
      pairs = []
      flags = word_compile.ParseAssignFlags(node.flags)

      if node.keyword == Id.Assign_Local:

core/expr_eval.py

@@ -485,14 +485,14 @@ def Eval(self, node):
        if op_id in (Id.BoolUnary_h, Id.BoolUnary_L):
          try:
            mode = os.lstat(s).st_mode
          except OSError as e:
          except OSError:
            return False

          return stat.S_ISLNK(mode)

        try:
          mode = os.stat(s).st_mode
        except OSError as e:
        except OSError:
          # TODO: Signal extra debug information?
          #self._AddErrorContext("Error from stat(%r): %s" % (s, e))
          return False

core/process.py

@@ -202,7 +202,6 @@ def Push(self, redirects, waiter):
    self.stack.append(new_frame)
    self.cur_frame = new_frame

    ok = True
    for r in redirects:
      #log('apply %s', r)
      if not self._ApplyRedirect(r, waiter):

core/state.py

@@ -528,7 +528,6 @@ def _FindCellAndNamespace(self, name, lookup_mode, is_read=False):
      namespace: The namespace it should be set to or deleted from.
    """
    if lookup_mode == scope_e.Dynamic:
      found = False
      for i in range(len(self.var_stack) - 1, -1, -1):
        frame = self.var_stack[i]
        if frame.readonly and not is_read:

core/util.py

@@ -18,7 +18,6 @@
import pwd
import sys

import os
if not os.getenv('_OVM_DEPS'):
  import inspect
  import types

core/word_eval.py

@@ -706,7 +706,7 @@ def _EvalWordToParts(self, word, quoted, part_vals):
        "Expected CompoundWord, got %s" % word

    for p in word.parts:
      v = self._EvalWordPart(p, part_vals, quoted=quoted)
      self._EvalWordPart(p, part_vals, quoted=quoted)

  def EvalWordToString(self, word, do_fnmatch=False, decay=False):
    """

test/lint.sh

@@ -58,21 +58,6 @@ bin-pep8() {
  ~/.local/bin/pep8 "$@"
}

# disable:
# E226: missing whitespace around arithmetic -- I want to do i+1
# E302: expected two blank lines, found 1 (sometimes one is useful).
# E265: Although I agree with this style, some comments don't start with '# '
# E111,E114: we use 2 space indents, not 4
oil-pep8() {
  # These could be enabled.
  local temp=W291,E501,E303  # trailing whitespace, line too long, blank lines
  bin-pep8 --ignore E125,E701,E241,E121,E111,E114,E128,E262,E226,E302,E265,$temp "$@"
}

pep8-all() {
  oil-pep8 {asdl,bin,core,osh}/*.py "$@"
}

# Language independent
find-tabs() {
  # benchmarks/testdata should be excluded
@@ -100,12 +85,24 @@ bin-flake8() {
flake8-all() {
  local -a dirs=(asdl bin core osh)

  # Step 1: Stop the build if there are Python syntax errors or undefined names
  # Step 1: Stop the build if there are Python syntax errors, undefined names,
  # unused imports
  local fatal_errors='E901,E999,F821,F822,F823,F401'
  bin-flake8 "${dirs[@]}" \
    --count --select=E901,E999,F821,F822,F823,F401 --show-source --statistics
    --count --select "$fatal_errors" --show-source --statistics

  # Make unused variable fatal.  Hm there are some I want.
  #scripts/count.sh oil-osh-files | grep -F '.py' | xargs $0 bin-flake8 --select F841

  # Step 2: Style errors as warnings.
  local ignored='E125,E701,E241,E121,E111,E114,E128,E262,E226,E302,E265,E290,E202,E203,C901'

  # disable:
  # E226: missing whitespace around arithmetic -- I want to do i+1
  # E302: expected two blank lines, found 1 (sometimes one is useful).
  # E265: Although I agree with this style, some comments don't start with '# '
  # E111,E114: we use 2 space indents, not 4

  local ignored='E125,E701,E241,E121,E111,E114,E128,E262,E226,E302,E265,E290,E202,E203,C901,E261'
  # trailing whitespace, line too long, blank lines
  local ignored_for_now='W291,E501,E303'