Fix issue #1208: Separately identify import sections for each from import

Author: timothycrosley

isort/parse.py

@@ -432,21 +432,21 @@ def file_contents(contents: str, config: Config = DEFAULT_CONFIG) -> ParsedConte
 
             if type_of_import == "from":
                 import_from = just_imports.pop(0)
-                placed_module = finder(import_from)
-                if config.verbose and not config.only_modified:
-                    print(f"from-type place_module for {import_from} returned {placed_module}")
-
-                elif config.verbose:
-                    verbose_output.append(
-                        f"from-type place_module for {import_from} returned {placed_module}"
-                    )
-                if placed_module == "":
-                    warn(
-                        f"could not place module {import_from} of line {line} --"
-                        " Do you need to define a default section?"
-                    )
-                root = imports[placed_module][type_of_import]  # type: ignore
                 for import_name in just_imports:
+                    placed_module = finder(f"{import_from}.{import_name}")
+                    if config.verbose and not config.only_modified:
+                        print(f"from-type place_module for {import_from} returned {placed_module}")
+
+                    elif config.verbose:
+                        verbose_output.append(
+                            f"from-type place_module for {import_from} returned {placed_module}"
+                        )
+                    if placed_module == "":
+                        warn(
+                            f"could not place module {import_from} of line {line} --"
+                            " Do you need to define a default section?"
+                        )
+                    root = imports[placed_module][type_of_import]  # type: ignore
                     associated_comment = nested_comments.get(import_name)
                     if associated_comment:
                         categorized_comments["nested"].setdefault(import_from, {})[

isort/place.py

@@ -23,7 +23,7 @@ def module_with_reason(name: str, config: Config = DEFAULT_CONFIG) -> Tuple[str,
     return (
         _forced_separate(name, config)
         or _local(name, config)
-        or _known_pattern(name, config)
+        or known_pattern(name, config)
         or _src_path(name, config)
         or (config.default_section, "Default option in Config or universal default.")
     )
@@ -49,7 +49,8 @@ def _local(name: str, config: Config) -> Optional[Tuple[str, str]]:
     return None
 
 
-def _known_pattern(name: str, config: Config) -> Optional[Tuple[str, str]]:
+@lru_cache(maxsize=1000)
+def known_pattern(name: str, config: Config) -> Optional[Tuple[str, str]]:
     parts = name.split(".")
     module_names_to_check = (".".join(parts[:first_k]) for first_k in range(len(parts), 0, -1))
     for module_name_to_check in module_names_to_check:

tests/unit/test_isort.py

@@ -1038,8 +1038,8 @@ def test_forced_separate() -> None:
         "from django.core.urlresolvers import reverse\n"
         "from django.db import models\n"
         "from django.db.models.fields import FieldDoesNotExist\n"
-        "from django.utils import six\n"
         "\n"
+        "from django.utils import six\n"
         "from django.utils.deprecation import RenameMethodsBase\n"
         "from django.utils.encoding import force_str, force_text\n"
         "from django.utils.http import urlencode\n"