Add transform_filepath method. #12 #13

Author: fabiocaccamo

README.md

@@ -112,6 +112,7 @@ import fsutil
 -   [`split_filename`](#split_filename)
 -   [`split_filepath`](#split_filepath)
 -   [`split_path`](#split_path)
+-   [`transform_filepath`](#transform_filepath)
 -   [`write_file`](#write_file)
 -   [`write_file_json`](#write_file_json)
 
@@ -726,6 +727,13 @@ dirpath, filename = fsutil.split_filepath(path)
 path_names = fsutil.split_path(path)
 ```
 
+#### `transform_filepath`
+
+```python
+# Trasform a filepath by applying the provided optional changes.
+filepath = fsutil.transform_filepath(path, dirpath=None, basename=lambda b: slugify(b), extension="webp")
+```
+
 #### `write_file`
 
 ```python

fsutil/__init__.py

@@ -1339,6 +1339,63 @@ def split_path(path: PathIn) -> list[str]:
     return names
 
 
+def transform_filepath(
+    path: PathIn,
+    *,
+    dirpath: str | Callable[[str], str] | None = None,
+    basename: str | Callable[[str], str] | None = None,
+    extension: str | Callable[[str], str] | None = None,
+) -> str:
+    """
+    Trasform a filepath by applying the provided optional changes.
+
+    :param path: The path.
+    :type path: PathIn
+    :param dirpath: The new dirpath or a callable.
+    :type dirpath: str | Callable[[str], str] | None
+    :param basename: The new basename or a callable.
+    :type basename: str | Callable[[str], str] | None
+    :param extension: The new extension or a callable.
+    :type extension: str | Callable[[str], str] | None
+
+    :returns: The filepath with the applied changes.
+    :rtype: str
+    """
+
+    def _get_value(
+        new_value: str | Callable[[str], str] | None,
+        old_value: str,
+    ) -> str:
+        value = old_value
+        if new_value is not None:
+            if callable(new_value):
+                value = new_value(old_value)
+            elif isinstance(new_value, str):
+                value = new_value
+            else:
+                value = old_value
+        return value
+
+    if all([dirpath is None, basename is None, extension is None]):
+        raise ValueError(
+            "Invalid arguments: at least one of "
+            "'dirpath', 'basename' or 'extension' is required."
+        )
+    old_dirpath, old_filename = split_filepath(path)
+    old_basename, old_extension = split_filename(old_filename)
+    new_dirpath = _get_value(dirpath, old_dirpath)
+    new_basename = _get_value(basename, old_basename)
+    new_extension = _get_value(extension, old_extension)
+    if not any([new_dirpath, new_basename, new_extension]):
+        raise ValueError(
+            "Invalid arguments: at least one of "
+            "'dirpath', 'basename' or 'extension' is required."
+        )
+    new_filename = join_filename(new_basename, new_extension)
+    new_filepath = join_filepath(new_dirpath, new_filename)
+    return new_filepath
+
+
 def _write_file_atomic(
     path: PathIn,
     content: str,

tests/test.py

@@ -1222,6 +1222,83 @@ def test_split_path(self):
         s = "/root/a/b/c/Document.txt"
         self.assertEqual(fsutil.split_path(s), ["root", "a", "b", "c", "Document.txt"])
 
+    def test_transform_filepath_without_args(self):
+        s = "/root/a/b/c/Document.txt"
+        with self.assertRaises(ValueError):
+            (fsutil.transform_filepath(s),)
+
+    def test_transform_filepath_with_empty_str_args(self):
+        s = "/root/a/b/c/Document.txt"
+        self.assertEqual(
+            fsutil.transform_filepath(s, dirpath=""),
+            "Document.txt",
+        )
+        self.assertEqual(
+            fsutil.transform_filepath(s, basename=""),
+            "/root/a/b/c/txt",
+        )
+        self.assertEqual(
+            fsutil.transform_filepath(s, extension=""),
+            "/root/a/b/c/Document",
+        )
+        self.assertEqual(
+            fsutil.transform_filepath(
+                s, dirpath="/root/x/y/z/", basename="NewDocument", extension="xls"
+            ),
+            "/root/x/y/z/NewDocument.xls",
+        )
+        with self.assertRaises(ValueError):
+            (fsutil.transform_filepath(s, dirpath="", basename="", extension=""),)
+
+    def test_transform_filepath_with_str_args(self):
+        s = "/root/a/b/c/Document.txt"
+        self.assertEqual(
+            fsutil.transform_filepath(s, dirpath="/root/x/y/z/"),
+            "/root/x/y/z/Document.txt",
+        )
+        self.assertEqual(
+            fsutil.transform_filepath(s, basename="NewDocument"),
+            "/root/a/b/c/NewDocument.txt",
+        )
+        self.assertEqual(
+            fsutil.transform_filepath(s, extension="xls"),
+            "/root/a/b/c/Document.xls",
+        )
+        self.assertEqual(
+            fsutil.transform_filepath(s, extension=".xls"),
+            "/root/a/b/c/Document.xls",
+        )
+        self.assertEqual(
+            fsutil.transform_filepath(
+                s, dirpath="/root/x/y/z/", basename="NewDocument", extension="xls"
+            ),
+            "/root/x/y/z/NewDocument.xls",
+        )
+
+    def test_transform_filepath_with_callable_args(self):
+        s = "/root/a/b/c/Document.txt"
+        self.assertEqual(
+            fsutil.transform_filepath(s, dirpath=lambda d: f"{d}/x/y/z/"),
+            "/root/a/b/c/x/y/z/Document.txt",
+        )
+        self.assertEqual(
+            fsutil.transform_filepath(s, basename=lambda b: b.lower()),
+            "/root/a/b/c/document.txt",
+        )
+        self.assertEqual(
+            fsutil.transform_filepath(s, extension=lambda e: "xls"),
+            "/root/a/b/c/Document.xls",
+        )
+        self.assertEqual(
+            fsutil.transform_filepath(
+                s,
+                dirpath=lambda d: f"{d}/x/y/z/",
+                basename=lambda b: b.lower(),
+                extension=lambda e: "xls",
+            ),
+            "/root/a/b/c/x/y/z/document.xls",
+        )
+
     def test_write_file(self):
         path = self.temp_path("a/b/c.txt")
         fsutil.write_file(path, content="Hello World")