mysql -e "select * from table;" -h HOST --port=PORT -u USER -p DATABASE > mydumpfile.csv

Flask and Django are two popular web development frameworks for Python. While they share many similarities, there are some key differences between the two that make them suitable for different use cases.

Flask

First, let’s take a look at Flask. Flask is a microweb framework, which means it is a lightweight framework that provides only the essential features for web development. This makes Flask a good choice for developing small-scale applications or for building the backend of a web application. Flask is also known for its flexibility and simplicity, which makes it easy to learn and use.

Django

On the other hand, Django is a full-stack web framework. This means that it provides a complete set of tools and features for building a web application, from the frontend to the backend. This makes Django a good choice for developing large-scale, complex applications. Django is also known for its robustness and scalability, which makes it suitable for handling high traffic and large amounts of data.

Differences

One key difference between Flask and Django is their approach to web development. Flask uses a minimalist approach, which means that it provides only the core features necessary for web development. This allows developers to have full control over the design and implementation of their applications. In contrast, Django follows a batteries-included approach, which means that it provides a wide range of built-in features and tools. This allows developers to get started quickly and easily, but it also means that they may have less control over the design and implementation of their applications.

Another key difference between Flask and Django is their use of templates. Flask uses Jinja2 as its default templating engine, which allows developers to define the structure of their HTML pages using Python code. This makes it easy to reuse code and to incorporate logic into the HTML pages. In contrast, Django uses its own templating engine, which is based on the Django template language. This templating engine provides a number of useful features, such as filters and tags, which make it easy to manipulate and display data in the HTML pages.

Conclusion

In summary, Flask and Django are both powerful web development frameworks for Python. While they have many similarities, they also have some key differences that make them suitable for different use cases. Flask is a good choice for small-scale applications or for building the backend of a web application, while Django is a good choice for large-scale, complex applications.

Introduction

In MySQL, the character set of a database, table, or column specifies the set of characters that can be stored in that database, table, or column. The collation of a database, table, or column specifies the rules for comparing and sorting the characters in a particular character set.

First, set charset to utf8mb4 and collate to utf8mb4_unicode_ci.

Charset

CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci;

Database

ALTER DATABASE database_name CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci;

Table

ALTER TABLE table_name CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

Column

ALTER TABLE table_name MODIFY COLUMN col VARCHAR(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;

ALTER TABLE table_name MODIFY COLUMN col VARCHAR(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL;

ALTER TABLE table_name MODIFY COLUMN col VARCHAR(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL;

settings.py

Add charset to database options

DATABASES = {
    'default': {
        'ENGINE':'django.db.backends.mysql',
        ...
        'OPTIONS': {'charset': 'utf8mb4'},
    }
}

Conclusion

UTF8MB4_UNICODE_CI is a character set and collation in MySQL. The character set specifies the set of characters that can be used in a MySQL database, while the collation specifies the rules for comparing and sorting the characters in a particular character set.

UTF8MB4 is a character set that uses the UTF-8 encoding, which is a variable-width encoding that can represent any Unicode character. This character set supports up to four-byte characters, which allows it to represent a wider range of characters than the standard UTF-8 character set.

UNICODE_CI is a collation that specifies a case-insensitive comparison for Unicode characters. This means that the characters will be compared and sorted without considering their case (upper or lower). For example, the strings “Hello” and “hello” would be considered equal using this collation.

In summary, UTF8MB4_UNICODE_CI is a character set and collation that allows you to store and compare Unicode characters in a MySQL database in a case-insensitive manner, using the UTF-8 encoding. This can be useful if you need to support a wide range of characters, including emojis, in your database.

Links:

• Django Cook Book

It mimics the functionality of a KVM switch, which historically would allow you to use a single keyboard and mouse to control multiple computers by physically turning a dial on the box to switch the machine you’re controlling at any given moment. Barrier does this in software.

Usage

Install and run barrier on each machine that will be sharing. On the machine with the keyboard and mouse, make it the server.

OS support

Barrier works on:

• Windows 7, 8, 8.1, 10, and 11
• macOS
• Linux
• FreeBSD
• OpenBSD

Installing on macOS

On macOS you can install it using brew.

$ brew cask install barrier

Installing on Arch/Manjaro Linux

On Arch Linux you can install it using pacman.

$ pacman -S barrier

Links

• Barrier on Homebrew
• Barrier on Github

find /path/to/ -type f -mtime +30 -name '*.mp4' -execdir rm -- '{}' \;

• find: the unix command for finding files/directories/links and etc.

• /path/to/: the directory to start your search in.

• -type f: only find files.

• -name ‘*.mp4’: list files that ends with .mp4.

• -mtime +30: only consider the ones with modification time older than 30 days.

• -execdir … \;: for each such result found, do the following command in ….

• rm – ‘{}’: remove the file; the {} part is where the find result gets substituted into from the previous part.

Note: If you are using Python 3.3 or newer, the venv module is the preferred way to create and manage virtual environments. venv is included in the Python standard library and requires no additional installation.

Installing virtualenv

python3 -m pip install --user virtualenv

Creating a virtual environment

python3 -m venv env

Activating a virtual environment

source env/bin/activate

Install packages

pip install -r requirements.txt

Freeze requirements

pip freeze > requirements.txt

Leaving the virtual environment

deactivate

Reference:

• python.org

Add a rewrite rule to the VirtualHost section of your configuration file similar to the following:

<VirtualHost *:80>
    RewriteEngine On
    RewriteCond %{HTTP:X-Forwarded-Proto} =http
    RewriteRule .* https://%{HTTP:Host}%{REQUEST_URI} [L,R=permanent]
</VirtualHost>

Save your Apache configuration file.

Restart Apache.

Reference:

• AWS

Setup

SSH into your instance and become root

$ sudo su -

Go to the the /usr/local/bin directory

$ cd /usr/local/bin

Inside the /usr/local/bin directory, create an “ffmpeg” directory

$ mkdir ffmpeg

Go into the new directory

$ cd ffmpeg

Go to static build directory at http://ffmpeg.gusari.org/static/64bit/ and pick the latest version of FFMPEG.

$ wget https://johnvansickle.com/ffmpeg/releases/ffmpeg-release-amd64-static.tar.xz

The file should now be in /usr/local/bin/ffmpeg. Untar it…

$ tar -xf ffmpeg-release-amd64-static.tar.xz

Move files

$ mv ffmpeg-release-amd64-static/* .

If you want to be able to execute FFMPEG from any directory, simply create a symlink into /usr/bin like this:

$ ln -s /usr/local/bin/ffmpeg/ffmpeg /usr/bin/ffmpeg

Now, you should be able to run the command “ffmpeg” from anywhere

Reference

• nbcnc on AWS Forums
• Vivek Maskara on Medium

Example:

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:lineSpacingMultiplier="0.7">

More on stackoverflow.

1. install brew package manager. http://mxcl.github.com/homebrew/

2. install the following packages.

$ brew install fuse4x
$ brew install ntfs-3g

1. copy the following file and set permissions.

$ sudo cp -rfX /usr/local/Cellar/fuse4x-kext/0.8.14/Library/Extensions/fuse4x.kext /System/Library/Extensions
$ sudo chmod +s /System/Library/Extensions/fuse4x.kext/Support/load_fuse4x

1. backup the mount script.

$ sudo mv /sbin/mount_ntfs /sbin/mount_ntfs.orig

1. create a new mount script and set permissions.

$ sudo touch /sbin/mount_ntfs
$ sudo chmod 0755 /sbin/mount_ntfs
$ sudo chown 0:0 /sbin/mount_ntfs
$ sudo nano /sbin/mount_ntfs

1. mount script content.

#!/bin/bash

VOLUME_NAME="${@:$#}"
VOLUME_NAME=${VOLUME_NAME#/Volumes/}
USER_ID=501
GROUP_ID=20
TIMEOUT=20

if [ `/usr/bin/stat -f "%u" /dev/console` -eq 0 ]; then
        USERNAME=`/usr/bin/defaults read /library/preferences/com.apple.loginwindow | /usr/bin/grep autoLoginUser | /usr/bin/awk '{ print $3 }' | /usr/bin/sed 's/;//'`
        if [ "$USERNAME" = "" ]; then
                until [ `stat -f "%u" /dev/console` -ne 0 ] || [ $TIMEOUT -eq 0 ]; do
                        sleep 1
                        let TIMEOUT--
                done
                if [ $TIMEOUT -ne 0 ]; then
                        USER_ID=`/usr/bin/stat -f "%u" /dev/console`
                        GROUP_ID=`/usr/bin/stat -f "%g" /dev/console`
                fi
        else
                USER_ID=`/usr/bin/id -u $USERNAME`
                GROUP_ID=`/usr/bin/id -g $USERNAME`
        fi
else
        USER_ID=`/usr/bin/stat -f "%u" /dev/console`
        GROUP_ID=`/usr/bin/stat -f "%g" /dev/console`
fi

/usr/local/bin/ntfs-3g \
        -o volname="${VOLUME_NAME}" \
        -o local \
        -o noappledouble \
        -o negative_vncache \
        -o auto_xattr \
        -o auto_cache \
        -o noatime \
        -o windows_names \
        -o user_xattr \
        -o inherit \
        -o uid=$USER_ID \
        -o gid=$GROUP_ID \
        -o allow_other \
        "$@" &> /var/log/ntfsmnt.log

exit $?;

References:

1. http://psionides.eu/2011/11/20/how-to-fix-ntfs-support-on-osx-lion/
2. http://fernandoff.posterous.com/ntfs-write-support-on-osx-lion-with-ntfs-3g-f