imports

func PythonRelativeImport ¶

func PythonRelativeImport(fromPkg, toPkg string) string

PythonRelativeImport returns a Python relative dotted path from fromPkg to toPkg. Both args are absolute dotted package paths.

Output:

• Leading dots encode the climb from fromPkg up to the common ancestor of fromPkg and toPkg, plus one. The "plus one" matches Python's convention where the first dot denotes the caller's own package (e.g. "from . import X" means "from caller-pkg import X").
• Trailing segments are the path from the common ancestor down to toPkg, joined by dots.

Examples:

PythonRelativeImport("a", "a.b") == ".b"
PythonRelativeImport("a.b", "a.b") == "."
PythonRelativeImport("a.b", "a.b.c") == ".c"
PythonRelativeImport("a.b.c","a.b") == ".."
PythonRelativeImport("a.b.c", "a.b.d") == "..d"
PythonRelativeImport("a.b.c","a.d") == "...d"

Empty fromPkg or toPkg are treated as zero-segment paths.