Execuation Order¶
A SQL statement selects rows and columns from a big (rectangular) table.
You put columns that you want to select after SELECT
and rows you want to select after FROM.
A SQL statement is executed as follows.
First,
the (INNER|LEFT|RIGHT|FULL) JOIN (ON) is executed if any (see more explanation later).
Second,
the WHERE
Convert Format of Videos Using Using Python
Convert a Video to MP4 Using python-opencv¶
The code below converts a MOV vidoe file to a MP4 vidoe file using OpenCV in Python.
Extract Images from Video Using OpenCV in Python
Tips and Traps¶
- Most videoes have a FPS of 24. Some videos have higher FPS (e.g., 30 or 60) so that they can capture motions better. A record video on a computer has a FPS of the refresh rate of the monitor, which is usually 60. You can get the FPS of a video using OpenCV in Python.
Get User's Information in Python
Encoding and Decoding Base64 String in Python
Packaging Python Dependencies for PySpark Using python-build-standalone
You can build a portable Python environment following steps below.
-
Install python-build-standalone.
-
Install Python packages using pip of the installed python-build-standalone distribution.
-
Pack the whole python-build-standalone directory into a compressed file, e.g.,
env.tar.gz.
The GitHub repo dclong/python-portable has good examples of building portable Python environments leveraging …