Initial work toward cimport support

2 files changed, 50 insertions, 15 deletions

diff --git a/isort/api.py b/isort/api.py
index 0aae7711..b7126999 100644
--- a/isort/api.py
+++ b/isort/api.py
@@ -18,6 +18,9 @@ from .io import File
 from .settings import DEFAULT_CONFIG, FILE_SKIP_COMMENTS, Config
 
 IMPORT_START_IDENTIFIERS = ("from ", "from.import", "import ", "import*")
+
+CIMPORT_IDENTIFIERS = ("cimport ", "cimport*", "from.cimport")
+IMPORT_START_IDENTIFIERS = ("from ", "from.import", "import ", "import*") + CIMPORT_IDENTIFIERS
 COMMENT_INDICATORS = ('"""', "'''", "'", '"', "#")
 
 
@@ -149,6 +152,7 @@ def sort_imports(
     line_separator: str = config.line_ending
     add_imports: List[str] = [format_natural(addition) for addition in config.add_imports]
     import_section: str = ""
+    next_import_section: str = ""
     in_quote: str = ""
     first_comment_index_start: int = -1
     first_comment_index_end: int = -1
@@ -158,6 +162,7 @@ def sort_imports(
     section_comments = [f"# {heading}" for heading in config.import_headings.values()]
     indent: str = ""
     isort_off: bool = False
+    cimports: bool = False
 
     for index, line in enumerate(chain(input_stream, (None,))):
         if line is None:
@@ -226,7 +231,7 @@ def sort_imports(
                     contains_imports = True
 
                     indent = line[: -len(line.lstrip())]
-                    import_section += line
+                    import_statement = line
                     while stripped_line.endswith("\\") or (
                         "(" in stripped_line and ")" not in stripped_line
                     ):
@@ -234,12 +239,32 @@ def sort_imports(
                             while stripped_line and stripped_line.endswith("\\"):
                                 line = input_stream.readline()
                                 stripped_line = line.strip().split("#")[0]
-                                import_section += line
+                                import_statement += line
                         else:
                             while ")" not in stripped_line:
                                 line = input_stream.readline()
                                 stripped_line = line.strip().split("#")[0]
-                                import_section += line
+                                import_statement += line
+
+                    cimport_statement: bool = False
+                    if (
+                        import_statement.lstrip().startswith(CIMPORT_IDENTIFIERS)
+                        or "cimport " in import_statement
+                        or "cimport*" in import_statement
+                        or "cimport(" in import_statement
+                    ):
+                        cimport_statement = True
+
+                    if cimport_statement != cimports:
+                        if import_section:
+                            next_import_section = import_statement
+                            import_statement = ""
+                            not_imports = True
+                            line = ""
+                        else:
+                            cimports = cimport_statement
+
+                    import_section + import_statement
                 else:
                     not_imports = True
 
@@ -277,7 +302,10 @@ def sort_imports(
                             line.lstrip() for line in import_section.split(line_separator)
                         )
                     sorted_import_section = output.sorted_imports(
-                        parse.file_contents(import_section, config=config), config, extension
+                        parse.file_contents(import_section, config=config),
+                        config,
+                        extension,
+                        import_type="cimport" if cimports else "import",
                     )
                     if indent:
                         sorted_import_section = (
@@ -291,7 +319,10 @@ def sort_imports(
                     indent = ""
 
                 contains_imports = False
-                import_section = ""
+                if next_import_section:
+                    cimports = not cimports
+                import_section = next_import_section
+                next_import_section = ""
             else:
                 output_stream.write(line)
                 not_imports = False
diff --git a/isort/parse.py b/isort/parse.py
index 6089c08b..3bfa3b0f 100644
--- a/isort/parse.py
+++ b/isort/parse.py
@@ -11,8 +11,6 @@ from isort.settings import DEFAULT_CONFIG, Config
 from .comments import parse as parse_comments
 from .finders import FindersManager
 
-IMPORT_START_IDENTIFIERS = ("from ", "from.import", "import ", "import*")
-
 if TYPE_CHECKING:
     from mypy_extensions import TypedDict
 
@@ -46,8 +44,10 @@ def _normalize_line(raw_line: str) -> Tuple[str, str]:
     Returns (normalized_line: str, raw_line: str)
     """
     line = raw_line.replace("from.import ", "from . import ")
+    line = raw_line.replace("from.cimport ", "from . cimport ")
     line = line.replace("import*", "import *")
     line = line.replace(" .import ", " . import ")
+    line = line.replace(" .cimport ", " . cimport ")
     line = line.replace("\t", " ")
     return (line, raw_line)
 
@@ -56,7 +56,7 @@ def import_type(line: str) -> Optional[str]:
     """If the current line is an import line it will return its type (from or straight)"""
     if "isort:skip" in line or "isort: skip" in line or "NOQA" in line:
         return None
-    elif line.startswith("import "):
+    elif line.startswith(("import ", "cimport ")):
         return "straight"
     elif line.startswith("from "):
         return "from"
@@ -68,7 +68,7 @@ def _strip_syntax(import_string: str) -> str:
     for remove_syntax in ["\\", "(", ")", ","]:
         import_string = import_string.replace(remove_syntax, " ")
     import_list = import_string.split()
-    for key in ("from", "import"):
+    for key in ("from", "import", "cimport"):
         if key in import_list:
             import_list.remove(key)
     import_string = " ".join(import_list)
@@ -108,7 +108,7 @@ def skip_line(
 
     if ";" in line:
         for part in (part.strip() for part in line.split(";")):
-            if part and not part.startswith("from ") and not part.startswith("import "):
+            if part and not part.startswith("from ") and not part.startswith(("import ", "cimport ")):
                 skip_line = True
 
     return (bool(skip_line or in_quote), in_quote)
@@ -267,18 +267,22 @@ def file_contents(contents: str, config: Config = DEFAULT_CONFIG) -> ParsedConte
                         and new_comment
                     ):
                         nested_comments[stripped_line] = comments[-1]
-                    if import_string.strip().endswith(" import") or line.strip().startswith(
-                        "import "
-                    ):
+                    if import_string.strip().endswith((" import", " cimport")) or line.strip().startswith(("import ", "cimport ")):
                         import_string += line_separator + line
                     else:
                         import_string = import_string.rstrip().rstrip("\\") + " " + line.lstrip()
 
             if type_of_import == "from":
+                cimport: bool
                 import_string = import_string.replace("import(", "import (")
-                parts = import_string.split(" import ")
+                if " cimport " in import_string:
+                    parts = import_string.split(" cimport ")
+                    cimport = True
+                else:
+                    parts = import_string.split(" import ")
+                    cimport = False
                 from_import = parts[0].split(" ")
-                import_string = " import ".join(
+                import_string = " cimport " if cimport else " import ".join(
                     [from_import[0] + " " + "".join(from_import[1:])] + parts[1:]
                 )