diff --git a/av/video/frame.pyx b/av/video/frame.pyx
index 6c8b247b8..9498938e6 100644
--- a/av/video/frame.pyx
+++ b/av/video/frame.pyx
@@ -381,24 +381,24 @@ cdef class VideoFrame(Frame):
         return frame
 
     @staticmethod
-    def from_numpy_buffer(array, format='rgb24'):
-        if format in ["rgb24", "bgr24"]:
+    def from_numpy_buffer(array, format="rgb24"):
+        if format in ("rgb24", "bgr24"):
             check_ndarray(array, 'uint8', 3)
             check_ndarray_shape(array, array.shape[2] == 3)
             height, width = array.shape[:2]
-        elif format in ('gray', 'gray8', 'rgb8', 'bgr8'):
-            check_ndarray(array, 'uint8', 2)
+        elif format in ("gray", "gray8", "rgb8", "bgr8"):
+            check_ndarray(array, "uint8", 2)
             height, width = array.shape[:2]
-        elif format in ["yuv420p", "yuvj420p", "nv12"]:
-            check_ndarray(array, 'uint8', 2)
+        elif format in ("yuv420p", "yuvj420p", "nv12"):
+            check_ndarray(array, "uint8", 2)
             check_ndarray_shape(array, array.shape[0] % 3 == 0)
             check_ndarray_shape(array, array.shape[1] % 2 == 0)
             height, width = array.shape[:2]
             height = height // 6 * 4
         else:
-            raise ValueError('Conversion from numpy array with format `%s` is not yet supported' % format)
+            raise ValueError(f"Conversion from numpy array with format `{format}` is not yet supported")
 
-        if not array.flags['C_CONTIGUOUS']:
+        if not array.flags["C_CONTIGUOUS"]:
             raise ValueError("provided array must be C_CONTIGUOUS")
 
         frame = alloc_video_frame()
diff --git a/av/video/plane.pyx b/av/video/plane.pyx
index 3d0a523b0..de8959e67 100644
--- a/av/video/plane.pyx
+++ b/av/video/plane.pyx
@@ -2,11 +2,9 @@ from av.video.frame cimport VideoFrame
 
 
 cdef class VideoPlane(Plane):
-
     def __cinit__(self, VideoFrame frame, int index):
-
         # The palette plane has no associated component or linesize; set fields manually
-        if frame.format.name == 'pal8' and index == 1:
+        if frame.format.name == "pal8" and index == 1:
             self.width = 256
             self.height = 1
             self.buffer_size = 256 * 4
@@ -19,7 +17,7 @@ cdef class VideoPlane(Plane):
                 self.height = component.height
                 break
         else:
-            raise RuntimeError('could not find plane %d of %r' % (index, frame.format))
+            raise RuntimeError("could not find plane %d of %r" % (index, frame.format))
 
         # Sometimes, linesize is negative (and that is meaningful). We are only
         # insisting that the buffer size be based on the extent of linesize, and
@@ -43,7 +41,7 @@ cdef class YUVPlanes(VideoPlane):
     def __cinit__(self, VideoFrame frame, int index):
         if index != 0:
             raise RuntimeError("YUVPlanes only supports index 0")
-        if frame.format.name not in ['yuvj420p', 'yuv420p']:
+        if frame.format.name not in ("yuvj420p", "yuv420p"):
             raise RuntimeError("YUVPlane only supports yuv420p and yuvj420p")
         if frame.ptr.linesize[0] < 0:
             raise RuntimeError("YUVPlane only supports positive linesize")