No module named 'yaml'

pip install pyyaml


delete over than specific megabyte in git history using bfg

firstly, install bfg

on mac

> brew install bfg

delete object if over than 50m in git commit history

> bfg --strip-blobs-bigger-than 50M

make sure & apply .gitignore

First, to check what files are you actually tracking
> git ls-tree --name-only --full-tree -r HEAD

Let say that you found unwanted files in a directory like cache/ so, it's safer to target that directory instead of all of your files.
So instead of:

> git rm -r --cached .

It's safer to target the unwanted file or directory:
> git rm -r --cached cache/

Then proceed to add all changes:
> git add .

and commit
> git commit -m ".gitignore is now working"

list up and sorting file(object) size in git / command

 use following cmd:

> git rev-list --objects --all | git cat-file --batch-check='%(objecttype) %(objectname) %(objectsize) %(rest)' | sed -n 's/^blob //p' | sort --numeric-sort --key=2 | cut -c 1-12,41- | $(command -v gnumfmt || echo numfmt) --field=2 --to=iec-i --suffix=B --padding=7 --round=nearest


get YouTube video url from channel name, python youtube-dl library


install youtube-dl package first.

pip install YouTube-dl


import subprocess
direct_output = subprocess.check_output('youtube-dl --get-id https://www.youtube.com/channel/UCAwWYtU_DEdRFxEHl9879dRYBfQ/videos --no-check-certificate', shell=True)
Lines = direct_output.decode()
idv = Lines.split('\n')
play_url_list = []
for idv in Lines.split('\n'):
if idv == '':
play_url_list.append( 'https://www.youtube.com/watch?v={}'.format(idv) )


Thank you.

Download or streaming YouTube video through cv2, python sample code

firstly, install pafy python package

> pip install pafy

if you some this related error "youtube_dl", install this. pafy works based on this package.

> pip install youtube-dl

you can check youtube-dl version:

> youtube-dl --version

if you also have some certification error, you can use --no-check-certification option
try this and test, this command will download video.

> sudo youtube-dl --no-check-certificate https://www.youtube.com/watch?v=N8A-BxTfTaY

ok then everything will be work using following code:

import pafy
from matplotlib import pyplot as plt
import cv2

url = "https://www.youtube.com/watch?v=TKbNDqcgjzw"
video = pafy.new(url, ydl_opts={'nocheckcertificate': True})
best = video.getbest(preftype="mp4")

cap = cv2.VideoCapture()

# Capture frame-by-frame
ret, frame = cap.read()
# Display the resulting frame
if cv2.waitKey(1) & 0xFF == ord('q'):

# When everything done, release the capture

Thank you.


python notebook clear output


from IPython.display import clear_output

for i in range(10):
    print("Hello World!")