Clean up unused imports for the peg generator module (GH-19891)

Tools/peg_generator/pegen/build.py

@@ -1,12 +1,11 @@
 import pathlib
 import shutil
 import tokenize
-import sys
 import sysconfig
 import tempfile
 import itertools
 
-from typing import Optional, Tuple, List, IO, Iterator, Set, Dict
+from typing import Optional, Tuple, List, IO, Set, Dict
 
 from pegen.c_generator import CParserGenerator
 from pegen.grammar import Grammar

Tools/peg_generator/pegen/c_generator.py

@@ -1,7 +1,7 @@
 import ast
 from dataclasses import dataclass, field
 import re
-from typing import IO, Any, Dict, List, Optional, Set, Text, Tuple
+from typing import Any, Dict, IO, Optional, List, Text, Tuple, Set
 from enum import Enum
 
 from pegen import grammar

Tools/peg_generator/pegen/first_sets.py

@@ -1,10 +1,9 @@
 #!/usr/bin/env python3.8
 
 import argparse
-import collections
 import pprint
 import sys
-from typing import Optional, Set, Dict
+from typing import Set, Dict
 
 from pegen.build import build_parser
 from pegen.grammar import (

Tools/peg_generator/pegen/grammar.py

@@ -4,7 +4,6 @@ from abc import abstractmethod
 from typing import (
     AbstractSet,
     Any,
-    Callable,
     Dict,
     Iterable,
     Iterator,
@@ -13,11 +12,9 @@ from typing import (
     Set,
     Tuple,
     TYPE_CHECKING,
-    TypeVar,
     Union,
 )
 
-from pegen.parser import memoize, Parser
 
 if TYPE_CHECKING:
     from pegen.parser_generator import ParserGenerator

Tools/peg_generator/pegen/grammar_visualizer.py

@@ -1,7 +1,7 @@
 import argparse
 import sys
 
-from typing import Any, Iterator, Iterable, Callable
+from typing import Any, Iterator, Callable
 
 from pegen.build import build_parser
 from pegen.grammar import Grammar, Rule

Tools/peg_generator/scripts/ast_timings.py

@@ -1,8 +1,6 @@
 import ast
 import sys
 import time
-import token
-import tokenize
 
 from pegen.testutil import print_memstats
 

Tools/peg_generator/scripts/benchmark.py

@@ -4,7 +4,6 @@ import argparse
 import ast
 import sys
 import os
-import resource
 from time import time
 
 import memory_profiler

Tools/peg_generator/scripts/find_max_nesting.py

@@ -13,11 +13,7 @@ INITIAL_NESTING_DEPTH, or NESTED_INCR_AMT variables.
 
 Usage: python -m scripts.find_max_nesting
 """
-import os
 import sys
-from tempfile import TemporaryDirectory
-from pathlib import Path
-from typing import Any
 
 from _peg_parser import parse_string
 

Tools/peg_generator/scripts/test_parse_directory.py

@@ -4,7 +4,6 @@ import argparse
 import ast
 import os
 import sys
-import tempfile
 import time
 import traceback
 from glob import glob