bazel-skylib/docs/paths_doc.md

paths.basename

paths.basename(p)

Returns the basename (i.e., the file portion) of a path.

Note that if p ends with a slash, this function returns an empty string. This matches the behavior of Python's os.path.basename, but differs from the Unix basename command (which would return the path segment preceding the final slash).

Parameters

p	required. The path whose basename should be returned.

paths.dirname

paths.dirname(p)

Returns the dirname of a path.

The dirname is the portion of p up to but not including the file portion (i.e., the basename). Any slashes immediately preceding the basename are not included, unless omitting them would make the dirname empty.

Parameters

p	required. The path whose dirname should be returned.

paths.is_absolute

paths.is_absolute(path)

Returns True if path is an absolute path.

Parameters

path	required. A path (which is a string).

paths.join

paths.join(path, others)

Joins one or more path components intelligently.

This function mimics the behavior of Python's os.path.join function on POSIX platform. It returns the concatenation of path and any members of others, inserting directory separators before each component except the first. The separator is not inserted if the path up until that point is either empty or already ends in a separator.

If any component is an absolute path, all previous components are discarded.

Parameters

path	required. A path segment.
others	optional. Additional path segments.

paths.normalize

paths.normalize(path)

Normalizes a path, eliminating double slashes and other redundant segments.

This function mimics the behavior of Python's os.path.normpath function on POSIX platforms; specifically:

• If the entire path is empty, "." is returned.
• All "." segments are removed, unless the path consists solely of a single "." segment.
• Trailing slashes are removed, unless the path consists solely of slashes.
• ".." segments are removed as long as there are corresponding segments earlier in the path to remove; otherwise, they are retained as leading ".." segments.
• Single and double leading slashes are preserved, but three or more leading slashes are collapsed into a single leading slash.
• Multiple adjacent internal slashes are collapsed into a single slash.

Parameters

path	required. A path.

paths.relativize

paths.relativize(path, start)

Returns the portion of path that is relative to start.

Because we do not have access to the underlying file system, this implementation differs slightly from Python's os.path.relpath in that it will fail if path is not beneath start (rather than use parent segments to walk up to the common file system root).

Relativizing paths that start with parent directory references only works if the path both start with the same initial parent references.

Parameters

path	required. The path to relativize.
start	required. The ancestor path against which to relativize.

paths.replace_extension

paths.replace_extension(p, new_extension)

Replaces the extension of the file at the end of a path.

If the path has no extension, the new extension is added to it.

Parameters

p	required. The path whose extension should be replaced.
new_extension	required. The new extension for the file. The new extension should begin with a dot if you want the new filename to have one.

paths.split_extension

paths.split_extension(p)

Splits the path p into a tuple containing the root and extension.

Leading periods on the basename are ignored, so path.split_extension(".bashrc") returns (".bashrc", "").

Parameters

p	required. The path whose root and extension should be split.