find_package() — flask Function Reference

Architecture documentation for the find_package() function in scaffold.py from the flask codebase.

Function python ApplicationCore Scaffolding calls 1 called by 1

Entity Profile

ApplicationCore→ Scaffolding→ find_package() — flask Function Reference

Dependency Diagram

graph TD
  4edb5aa7_d577_d1ba_2a86_d1b146357835["find_package()"]
  b48dce3f_427c_079b_4c4a_8f5873f5b51f["scaffold.py"]
  4edb5aa7_d577_d1ba_2a86_d1b146357835 -->|defined in| b48dce3f_427c_079b_4c4a_8f5873f5b51f
  5d914b38_d2af_c173_db31_3a2d1e8e567d["auto_find_instance_path()"]
  5d914b38_d2af_c173_db31_3a2d1e8e567d -->|calls| 4edb5aa7_d577_d1ba_2a86_d1b146357835
  3e63b545_7895_fecc_eae5_b9d8a7667c97["_find_package_path()"]
  4edb5aa7_d577_d1ba_2a86_d1b146357835 -->|calls| 3e63b545_7895_fecc_eae5_b9d8a7667c97
  style 4edb5aa7_d577_d1ba_2a86_d1b146357835 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

src/flask/sansio/scaffold.py lines 754–792

def find_package(import_name: str) -> tuple[str | None, str]:
    """Find the prefix that a package is installed under, and the path
    that it would be imported from.

    The prefix is the directory containing the standard directory
    hierarchy (lib, bin, etc.). If the package is not installed to the
    system (:attr:`sys.prefix`) or a virtualenv (``site-packages``),
    ``None`` is returned.

    The path is the entry in :attr:`sys.path` that contains the package
    for import. If the package is not installed, it's assumed that the
    package was imported from the current working directory.
    """
    package_path = _find_package_path(import_name)
    py_prefix = os.path.abspath(sys.prefix)

    # installed to the system
    if pathlib.PurePath(package_path).is_relative_to(py_prefix):
        return py_prefix, package_path

    site_parent, site_folder = os.path.split(package_path)

    # installed to a virtualenv
    if site_folder.lower() == "site-packages":
        parent, folder = os.path.split(site_parent)

        # Windows (prefix/lib/site-packages)
        if folder.lower() == "lib":
            return parent, package_path

        # Unix (prefix/lib/pythonX.Y/site-packages)
        if os.path.basename(parent).lower() == "lib":
            return os.path.dirname(parent), package_path

        # something else (prefix/site-packages)
        return site_parent, package_path

    # not installed
    return None, package_path