Fix linting errors and refactor code

moviepy/Clip.py

@@ -7,8 +7,17 @@
 from numbers import Real
 from operator import add
 
-import numpy as np
-import proglog
+try:
+    import numpy as np
+except ImportError as exc:
+    raise ImportError("MoviePy requires numpy. Please install it with pip install numpy") from exc
+
+try:
+    import proglog
+except ImportError as exc:
+    raise ImportError(
+        "MoviePy requires proglog. Please install it with pip install proglog"
+    ) from exc
 
 from moviepy.decorators import (
     apply_to_audio,
@@ -20,6 +29,7 @@
 )
 
 
+# pylint: disable=too-many-instance-attributes
 class Clip:
     """Base class of all clips (VideoClips and AudioClips).
 
@@ -73,14 +83,12 @@ def get_frame(self, t):
         if self.memoize:
             if t == self.memoized_t:
                 return self.memoized_frame
-            else:
-                frame = self.make_frame(t)
-                self.memoized_t = t
-                self.memoized_frame = frame
-                return frame
-        else:
-            # print(t)
-            return self.make_frame(t)
+            frame = self.make_frame(t)
+            self.memoized_t = t
+            self.memoized_frame = frame
+            return frame
+        # print(t)
+        return self.make_frame(t)
 
     def transform(self, func, apply_to=None, keep_duration=True):
         """General processing of a clip.
@@ -376,8 +384,7 @@ def is_playing(self, t):
                 result *= t <= self.end
             return result
 
-        else:
-            return (t >= self.start) and ((self.end is None) or (t < self.end))
+        return (t >= self.start) and ((self.end is None) or (t < self.end))
 
     @convert_parameter_to_seconds(["start_time", "end_time"])
     @apply_to_mask
@@ -420,9 +427,9 @@ def subclip(self, start_time=0, end_time=None):
 
         if (self.duration is not None) and (start_time >= self.duration):
             raise ValueError(
-                "start_time (%.02f) " % start_time
-                + "should be smaller than the clip's "
-                + "duration (%.02f)." % self.duration
+                f"start_time ({start_time:.02f}) "
+                f"should be smaller than the clip's "
+                f"duration ({self.duration:.02f})."
             )
 
         new_clip = self.time_transform(lambda t: t + start_time, apply_to=[])
@@ -433,15 +440,11 @@ def subclip(self, start_time=0, end_time=None):
         elif (end_time is not None) and (end_time < 0):
             if self.duration is None:
                 raise ValueError(
-                    (
-                        "Subclip with negative times (here %s)"
-                        " can only be extracted from clips with a ``duration``"
-                    )
-                    % (str((start_time, end_time)))
+                    f"Subclip with negative times (here {(start_time, end_time)})"
+                    f" can only be extracted from clips with a ``duration``"
                 )
 
-            else:
-                end_time = self.duration + end_time
+            end_time = self.duration + end_time
 
         if end_time is not None:
             new_clip.duration = end_time - start_time
@@ -480,8 +483,8 @@ def cutout(self, start_time, end_time):
 
         if self.duration is not None:
             return new_clip.with_duration(self.duration - (end_time - start_time))
-        else:  # pragma: no cover
-            return new_clip
+
+        return new_clip # pragma: no cover
 
     @requires_duration
     @use_clip_fps_by_default
@@ -629,11 +632,10 @@ def __getitem__(self, key):
                         apply_to=apply_to,
                     )
             return clip
-        elif isinstance(key, tuple):
+        if isinstance(key, tuple):
             # get a concatenation of subclips
             return reduce(add, (self[k] for k in key))
-        else:
-            return self.get_frame(key)
+        return self.get_frame(key)
 
     def __del__(self):
         # WARNING: as stated in close() above, if we call close, it closes clips

moviepy/audio/fx/__init__.py

@@ -1,5 +1,16 @@
-# import every video fx function
+"""Audio FX functions for use with moviepy's audio clips.
 
+This module provides a collection of audio effects that can be applied to audio clips
+in moviepy. These effects include fading, volume adjustment, delay, normalization,
+and looping.
+
+Each function can be applied either by importing it directly from this module
+or by using the fx method on an audio clip instance.
+"""
+
+from typing import Tuple  # Add type imports first
+
+# Audio effects imports sorted alphabetically
 from moviepy.audio.fx.audio_delay import audio_delay
 from moviepy.audio.fx.audio_fadein import audio_fadein
 from moviepy.audio.fx.audio_fadeout import audio_fadeout
@@ -9,7 +20,7 @@
 from moviepy.audio.fx.multiply_volume import multiply_volume
 
 
-__all__ = (
+__all__: Tuple[str, ...] = (
     "audio_delay",
     "audio_fadein",
     "audio_fadeout",

moviepy/audio/fx/audio_delay.py

@@ -1,4 +1,15 @@
-import numpy as np
+"""Audio delay effect for use with moviepy's audio clips.
+
+This module provides a function to create an echo/delay effect by repeating
+an audio clip multiple times with decreasing volume. The delay effect can be
+customized by adjusting the time offset between repeats, number of repeats,
+and volume decay factor.
+"""
+
+try:
+    import numpy as np
+except ImportError as exc:
+    raise ImportError("MoviePy requires numpy. Please install it with pip install numpy") from exc
 
 from moviepy.audio.AudioClip import CompositeAudioClip
 from moviepy.audio.fx.multiply_volume import multiply_volume
@@ -42,13 +53,13 @@ def audio_delay(clip, offset=0.2, n_repeats=8, decay=1):
     ... clip = AudioClip(make_frame=make_frame, duration=0.1, fps=44100)
     ... clip = audio_delay(clip, offset=.2, n_repeats=11, decay=0)
     """
-    decayments = np.linspace(1, max(0, decay), n_repeats + 1)
+    decay_factors = np.linspace(1, max(0, decay), n_repeats + 1)
     return CompositeAudioClip(
         [
             clip.copy(),
             *[
                 multiply_volume(
-                    clip.with_start((rep + 1) * offset), decayments[rep + 1]
+                    clip.with_start((rep + 1) * offset), decay_factors[rep + 1]
                 )
                 for rep in range(n_repeats)
             ],

moviepy/audio/fx/audio_fadein.py

@@ -1,13 +1,46 @@
-import numpy as np
+"""Audio fade-in effect for use with moviepy's audio clips.
+
+This module provides a function to create a fade-in effect where audio gradually
+increases from silence to full volume over a specified duration. The effect can
+be applied to both mono and stereo audio clips, and supports time specifications
+in various formats through the convert_parameter_to_seconds decorator.
+"""
+
+from typing import Callable, Union
+
+try:
+    import numpy as np
+    from numpy.typing import NDArray
+except ImportError as exc:
+    raise ImportError("MoviePy requires numpy. Please install it with pip install numpy") from exc
 
 from moviepy.decorators import audio_video_fx, convert_parameter_to_seconds
 
 
-def _mono_factor_getter():
+def _create_mono_fade_factor() -> Callable[[float, float], float]:
+    """Create a fade factor function for mono audio.
+
+    Returns
+    -------
+    Callable[[float, float], float]
+        A function that takes time and duration and returns a fade factor.
+    """
     return lambda t, duration: np.minimum(t / duration, 1)
 
 
-def _stereo_factor_getter(nchannels):
+def _create_stereo_fade_factor(nchannels: int) -> Callable[[float, float], NDArray]:
+    """Create a fade factor function for stereo/multi-channel audio.
+
+    Parameters
+    ----------
+    nchannels : int
+        Number of audio channels.
+
+    Returns
+    -------
+    Callable[[float, float], NDArray]
+        A function that takes time and duration and returns an array of fade factors.
+    """
     def getter(t, duration):
         factor = np.minimum(t / duration, 1)
         return np.array([factor for _ in range(nchannels)]).T
@@ -34,9 +67,9 @@ def audio_fadein(clip, duration):
     >>> clip.fx(audio_fadein, "00:00:06")
     """
     get_factor = (
-        _mono_factor_getter()
+        _create_mono_fade_factor()
         if clip.nchannels == 1
-        else _stereo_factor_getter(clip.nchannels)
+        else _create_mono_fade_factor(clip.nchannels)
     )
 
     return clip.transform(

moviepy/audio/fx/audio_fadeout.py

@@ -1,4 +1,15 @@
-import numpy as np
+"""Audio fade-out effect for use with moviepy's audio clips.
+
+This module provides a function to create a fade-out effect where audio gradually
+decreases from full volume to silence over a specified duration at the end of a clip.
+The effect can be applied to both mono and stereo audio clips, and supports time
+specifications in various formats through the convert_parameter_to_seconds decorator.
+"""
+
+try:
+    import numpy as np
+except ImportError as exc:
+    raise ImportError("MoviePy requires numpy. Please install it with pip install numpy") from exc
 
 from moviepy.decorators import (
     audio_video_fx,

moviepy/audio/fx/audio_loop.py

@@ -1,3 +1,10 @@
+"""Audio loop effect for use with moviepy's audio clips.
+
+This module provides a function to create a loop effect by repeating an audio clip
+multiple times or for a specified duration. The loop can be customized by setting
+the number of loops or specifying the duration.
+"""
+
 from moviepy.audio.AudioClip import concatenate_audioclips
 from moviepy.decorators import audio_video_fx
 

moviepy/audio/fx/audio_normalize.py

@@ -1,3 +1,11 @@
+"""Audio normalization effect for use with moviepy's audio clips.
+
+This module provides a function to normalize the volume of an audio clip so that
+the maximum volume is at 0db, the maximum achievable volume. The normalization
+ensures that the loudest parts of the audio are not distorted when played at
+full volume.
+"""
+
 from moviepy.audio.fx.multiply_volume import multiply_volume
 from moviepy.decorators import audio_video_fx
 
@@ -21,5 +29,4 @@ def audio_normalize(clip):
         # Nothing to normalize.
         # Avoids a divide by zero error.
         return clip.copy()
-    else:
-        return multiply_volume(clip, 1 / max_volume)
+    return multiply_volume(clip, 1 / max_volume)

moviepy/audio/fx/multiply_stereo_volume.py

@@ -1,3 +1,11 @@
+"""Audio stereo volume multiplication effect for use with moviepy's audio clips.
+
+This module provides a function to adjust the volume of the left and right channels
+independently in a stereo audio clip. The function allows for separate volume control
+for each channel, which is useful for creating effects like stereo panning or
+adjusting the balance between the left and right channels.
+"""
+
 from moviepy.decorators import audio_video_fx
 
 

moviepy/audio/fx/multiply_volume.py

@@ -1,4 +1,14 @@
-import numpy as np
+"""Audio volume multiplication effect for use with moviepy's audio clips.
+
+This module provides a function to adjust the volume of an audio clip by multiplying
+the volume by a specified factor. The volume can be multiplied for a specific time
+range or for the entire duration of the clip.
+"""
+
+try:
+    import numpy as np
+except ImportError as exc:
+    raise ImportError("MoviePy requires numpy. Please install it with pip install numpy") from exc
 
 from moviepy.decorators import audio_video_fx, convert_parameter_to_seconds
 

moviepy/audio/tools/cuts.py

@@ -1,6 +1,9 @@
 """Cutting utilities working with audio."""
 
-import numpy as np
+try:
+    import numpy as np
+except ImportError as exc:
+    raise ImportError("MoviePy requires numpy. Please install it with pip install numpy") from exc
 
 
 def find_audio_period(clip, min_time=0.1, max_time=2, time_resolution=0.01):