[Python] OpenCV error when trying to capture frame every seconds

I am trying to capture an image every 5 seconds in Opencv using my webcam however I am getting an error whenever I try.

Python Code:

def imgcap():
cap = cv2.VideoCapture(0)
framerate = cap.get(5)
x=1

while(True):
# Capture frame-by-frame
ret, frame = cap.read()
cap.release()
# Our operations on the frame come here

filename = 'Captures/capture' + str(int(x)) + ".png"
x=x+1
cv2.imwrite(filename, frame)
time.sleep(5)
if cv2.waitKey(1) & 0xFF == ord('q'):
break

# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()

imgcap()


Error I am Getting:

File "vision.py", line 30, in <module>
imgcap()
File "vision.py", line 21, in imgcap
cv2.imwrite(filename, frame)
cv2.error: OpenCV(4.5.1) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-oduouqig\opencv\modules\imgcodecs\src\loadsave.cpp:753: error: (-215:Assertion failed) !_img.empty() in function 'cv::imwrite'

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