"""Fast stream based import identification.
Eventually this will likely replace parse.py
"""
from functools import partial
from pathlib import Path
from typing import Iterator, NamedTuple, Optional, TextIO, Tuple
from isort.parse import _normalize_line, _strip_syntax, skip_line
from .comments import parse as parse_comments
from .settings import DEFAULT_CONFIG, Config
STATEMENT_DECLARATIONS: Tuple[str, ...] = ("def ", "cdef ", "cpdef ", "class ", "@", "async def")
class Import(NamedTuple):
line_number: int
indented: bool
module: str
attribute: Optional[str] = None
alias: Optional[str] = None
cimport: bool = False
file_path: Optional[Path] = None
def statement(self) -> str:
import_cmd = "cimport" if self.cimport else "import"
if self.attribute:
import_string = f"from {self.module} {import_cmd} {self.attribute}"
else:
import_string = f"{import_cmd} {self.module}"
if self.alias:
import_string += f" as {self.alias}"
return import_string
def __str__(self) -> str:
return (
f"{self.file_path or ''}:{self.line_number} "
f"{'indented ' if self.indented else ''}{self.statement()}"
)
def imports(
input_stream: TextIO,
config: Config = DEFAULT_CONFIG,
file_path: Optional[Path] = None,
top_only: bool = False,
) -> Iterator[Import]:
"""Parses a python file taking out and categorizing imports."""
in_quote = ""
indexed_input = enumerate(input_stream)
for index, raw_line in indexed_input:
(skipping_line, in_quote) = skip_line(
raw_line, in_quote=in_quote, index=index, section_comments=config.section_comments
)
if top_only and not in_quote and raw_line.startswith(STATEMENT_DECLARATIONS):
break
if skipping_line:
continue
stripped_line = raw_line.strip().split("#")[0]
if stripped_line.startswith("raise") or stripped_line.startswith("yield"):
if stripped_line == "yield":
while not stripped_line or stripped_line == "yield":
try:
index, next_line = next(indexed_input)
except StopIteration:
break
stripped_line = next_line.strip().split("#")[0]
while stripped_line.endswith("\\"):
try:
index, next_line = next(indexed_input)
except StopIteration:
break
stripped_line = next_line.strip().split("#")[0]
continue # pragma: no cover
line, *end_of_line_comment = raw_line.split("#", 1)
statements = [line.strip() for line in line.split(";")]
if end_of_line_comment:
statements[-1] = f"{statements[-1]}#{end_of_line_comment[0]}"
for statement in statements:
line, _raw_line = _normalize_line(statement)
if line.startswith(("import ", "cimport ")):
type_of_import = "straight"
elif line.startswith("from "):
type_of_import = "from"
else:
continue # pragma: no cover
import_string, _ = parse_comments(line)
normalized_import_string = (
import_string.replace("import(", "import (").replace("\\", " ").replace("\n", " ")
)
cimports: bool = (
" cimport " in normalized_import_string
or normalized_import_string.startswith("cimport")
)
identified_import = partial(
Import,
index + 1, # line numbers use 1 based indexing
raw_line.startswith((" ", "\t")),
cimport=cimports,
file_path=file_path,
)
if "(" in line.split("#", 1)[0]:
while not line.split("#")[0].strip().endswith(")"):
try:
index, next_line = next(indexed_input)
except StopIteration:
break
line, _ = parse_comments(next_line)
import_string += "\n" + line
else:
while line.strip().endswith("\\"):
try:
index, next_line = next(indexed_input)
except StopIteration:
break
line, _ = parse_comments(next_line)
# Still need to check for parentheses after an escaped line
if "(" in line.split("#")[0] and ")" not in line.split("#")[0]:
import_string += "\n" + line
while not line.split("#")[0].strip().endswith(")"):
try:
index, next_line = next(indexed_input)
except StopIteration:
break
line, _ = parse_comments(next_line)
import_string += "\n" + line
else:
if import_string.strip().endswith(
(" import", " cimport")
) or line.strip().startswith(("import ", "cimport ")):
import_string += "\n" + line
else:
import_string = (
import_string.rstrip().rstrip("\\") + " " + line.lstrip()
)
if type_of_import == "from":
import_string = (
import_string.replace("import(", "import (")
.replace("\\", " ")
.replace("\n", " ")
)
parts = import_string.split(" cimport " if cimports else " import ")
from_import = parts[0].split(" ")
import_string = (" cimport " if cimports else " import ").join(
[from_import[0] + " " + "".join(from_import[1:])] + parts[1:]
)
just_imports = [
item.replace("{|", "{ ").replace("|}", " }")
for item in _strip_syntax(import_string).split()
]
direct_imports = just_imports[1:]
top_level_module = ""
if "as" in just_imports and (just_imports.index("as") + 1) < len(just_imports):
while "as" in just_imports:
attribute = None
as_index = just_imports.index("as")
if type_of_import == "from":
attribute = just_imports[as_index - 1]
top_level_module = just_imports[0]
module = top_level_module + "." + attribute
alias = just_imports[as_index + 1]
direct_imports.remove(attribute)
direct_imports.remove(alias)
direct_imports.remove("as")
just_imports[1:] = direct_imports
if attribute == alias and config.remove_redundant_aliases:
yield identified_import(top_level_module, attribute)
else:
yield identified_import(top_level_module, attribute, alias=alias)
else:
module = just_imports[as_index - 1]
alias = just_imports[as_index + 1]
just_imports.remove(alias)
just_imports.remove("as")
just_imports.remove(module)
if module == alias and config.remove_redundant_aliases:
yield identified_import(module)
else:
yield identified_import(module, alias=alias)
if just_imports:
if type_of_import == "from":
module = just_imports.pop(0)
for attribute in just_imports:
yield identified_import(module, attribute)
else:
for module in just_imports:
yield identified_import(module)
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