openCV imwrite writing 0 kb image frames - python-2.7

Question

I am running the below code to convert video into frames. Problem is it is creating Image files with 0 KB size and when I open it is not showing anything.. I don't understand what is creating the problem. Do I need to install any Image codecs?
'''
Using OpenCV takes a mp4 video and produces a number of images. I am using OpenCV 3.3.0 version and Python 2.7
Which will produce a folder called data with the images, There will be 2000+ images for example.mp4.
'''
import cv2
import numpy as np
import os
# Playing video from file:
try:
cap = cv2.VideoCapture('aa.mkv')
except:
print "Could not open video file"
raise
print cap.grab()
try:
if not os.path.exists('data'):
os.makedirs('data')
except OSError:
print ('Error: Creating directory of data')
currentFrame = 0
while(True):
# Capture frame-by-frame
ret, frame = cap.read()
if not frame is None:
# Saves image of the current frame in jpg file
name = './data/frame' + str(currentFrame) + '.jpg'
print ('Creating...' + name)
cv2.imwrite(name, frame)
#cv2.imshow(name, frame)
else:
break
# To stop duplicate images
currentFrame += 1
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()

Answer 1

You are not using imwrite function to write frames. Also your imshow function name is misspelled. I have made changes in your code. Try this:
import cv2
import numpy as np
import os
# Playing video from file:
cap = cv2.VideoCapture('aa.mkv')
try:
if not os.path.exists('data'):
os.makedirs('data')
except OSError:
print ('Error: Creating directory of data')
currentFrame = 0
while(True):
# Capture frame-by-frame
ret, frame = cap.read()
if not frame is None:
# Saves image of the current frame in jpg file
name = './data/frame' + str(currentFrame) + '.jpg'
print ('Creating...' + name)
cv2.imwrite(name, frame)
cv2.imshow(name, frame)
else:
break
# To stop duplicate images
currentFrame += 1
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()