initial commit and version 1.0

moviepy/video/fx/TimeSymmetrize.py

@@ -0,0 +1,22 @@
+from dataclasses import dataclass
+
+from moviepy.Clip import Clip
+from moviepy.Effect import Effect
+
+
+@dataclass
+class TimeSymmetrize(Effect):
+    """
+    Returns a clip that plays the current clip once forwards and
+    then once backwards. This is very practival to make video that
+    loop well, e.g. to create animated GIFs.
+    This effect is automatically applied to the clip's mask and audio
+    if they exist.
+    """
+
+    def apply(self, clip: Clip) -> Clip:
+        """Apply the effect to the clip."""
+        if clip.duration is None:
+            raise ValueError("Attribute 'duration' not set")
+
+        return clip + clip[::-1]