Screen is like a window manager for your console. It will allow you to keep multiple terminal sessions running and easily switch between them. It also protects you from disconnection, because the screen session doesn’t end when you get disconnected.

You’ll need to make sure that screen is installed on the server you are connecting to. If that server is Ubuntu or Debian, just use this command:

sudo apt-get install screen

Now you can start a new screen session by just typing screen at the command line. You’ll be shown some information about screen. Hit enter, and you’ll be at a normal prompt.

To disconnect (but leave the session running)

Hit Ctrl + A and then Ctrl + D in immediate succession. You will see the message [detached]

To reconnect to an already running session

screen -r

To reconnect to an existing session, or create a new one if none exists

screen -D -r

To create a new window inside of a running screen session

Hit Ctrl + A and then C in immediate succession. You will see a new prompt.

To switch from one screen window to another

Hit Ctrl + A and then Ctrl + A in immediate succession.

To list open screen windows

Hit Ctrl + A and then W in immediate succession

Tasks:  239 total,   1 running,  238 sleeping,   0 stopped,   0 zombie

This line tells you how many processes are running. If you are using laptops machines it’s not so interesting because you really are the only one using this machine.

Cpu(s):  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st

This line contains the CPU load. The first two numbers are how busy the system is doing computation (“us” stands for “user”) and how busy the system is doing system-y things like accessing disks or network (“sy” stands for “system”). We’ll talk more about this later.

Mem:   49457320k total,    3492174k used,  14535596k free,    1435148k buffers

This should be easy to understand – how much memory you’re using!

Swap:   539356k total,   28332k used,   836562k free,    29862014k cached

Swap is just on-disk memory that can be used to “swap” out programs from main memory. Again, we’ll talk about this later.:

PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  1 root      39   19  0  0  0 S  0.0  0.0   246:57.22 kipmi0
  2 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/0

And... finally! What’s actually running! The two most important numbers are the %CPU and %MEM towards the right, as well as the COMMAND. This tells you how compute- and memory-intensive your program is. Right now, nothing’s running so the numbers aren’t very interesting, but just wait until we run something...

Then I thaught it migh be a problem of graphical display and I opened the terminal out of curiosity, and I found out that there is no ~/Desktop folder at all. What happened? What do I need to do?

Then I google the problem and found this is a very common problem after updates. To fix this problem, follow these steps:

You need to edit the ~/.config/user-dirs.dirs file, and make sure the contents of the file are like the following:

XDG_DESKTOP_DIR="$HOME/Desktop"
XDG_DOWNLOAD_DIR="$HOME/Downloads"
XDG_TEMPLATES_DIR="$HOME/"
XDG_PUBLICSHARE_DIR="$HOME/Share"
XDG_DOCUMENTS_DIR="$HOME/Documents"
XDG_MUSIC_DIR="$HOME/Music"
XDG_PICTURES_DIR="$HOME/Pictures"
XDG_VIDEOS_DIR="$HOME/Videos"

Then restart nautilus:

killall nautilus

or

nautilus -q

Then, open nautilus via Unity menu (press the Super key) or using the run command (Alt+F2)

Use the Terminal or an Anaconda Prompt for the following steps.

1. To create an environment:

   conda create --name myenv
   

   NOTE: Replace myenv with the environment name.

2. When conda asks you to proceed, type y:

   proceed ([y]/n)?
   

This creates the myenv environment in /envs/. This environment uses the same version of Python that you are currently using, because you did not specify a version.

To create an environment with a specific version of Python:

conda create -n myenv python=3.4

To create an environment with a specific package:

conda create -n myenv scipy

OR:

conda create -n myenv python
conda install -n myenv scipy

To create an environment with a specific version of a package:

conda create -n myenv scipy=0.15.0

OR:

conda create -n myenv python
conda install -n myenv scipy=0.15.0

To create an environment with a specific version of Python and multiple packages:

conda create -n myenv python=3.4 scipy=0.15.0 astroid babel

TIP: Install all the programs that you want in this environment at the same time. Installing 1 program at a time can lead to dependency conflicts.

To automatically install pip or another program every time a new environment is created, add the default programs to the create_default_packages section of your .condarc configuration file. The default packages are installed every time you create a new environment. If you do not want the default packages installed in a particular environment, use the --no-default-packages flag:

conda create --no-default-packages -n myenv python

TIP: You can add much more to the conda create command. For details, run conda create --help.

➜ redundans git:(master) ✗ conda create --name py27 python=2.7
Solving environment: done

==> WARNING: A newer version of conda exists. <==
current version: 4.5.0
latest version: 4.5.2

Please update conda by running

$ conda update -n base conda

## Package Plan ##

environment location: /home/urbe/anaconda3/envs/py27

added / updated specs:
- python=2.7

The following packages will be downloaded:

package | build
---------------------------|-----------------
wheel-0.31.0 | py27_0 61 KB
python-2.7.15 | h1571d57_0 12.1 MB
certifi-2018.4.16 | py27_0 142 KB
sqlite-3.23.1 | he433501_0 1.5 MB
setuptools-39.1.0 | py27_0 582 KB
openssl-1.0.2o | h20670df_0 3.4 MB
pip-10.0.1 | py27_0 1.7 MB
ca-certificates-2018.03.07 | 0 124 KB
------------------------------------------------------------
Total: 19.6 MB

The following NEW packages will be INSTALLED:

ca-certificates: 2018.03.07-0
certifi: 2018.4.16-py27_0
libedit: 3.1-heed3624_0
libffi: 3.2.1-hd88cf55_4
libgcc-ng: 7.2.0-hdf63c60_3
libstdcxx-ng: 7.2.0-hdf63c60_3
ncurses: 6.0-h9df7e31_2
openssl: 1.0.2o-h20670df_0
pip: 10.0.1-py27_0
python: 2.7.15-h1571d57_0
readline: 7.0-ha6073c6_4
setuptools: 39.1.0-py27_0
sqlite: 3.23.1-he433501_0
tk: 8.6.7-hc745277_3
wheel: 0.31.0-py27_0
zlib: 1.2.11-ha838bed_2

Proceed ([y]/n)? y

Downloading and Extracting Packages
wheel 0.31.0: #################################################################################################################################################################################################### | 100%
python 2.7.15: ################################################################################################################################################################################################### | 100%
certifi 2018.4.16: ############################################################################################################################################################################################### | 100%
sqlite 3.23.1: ################################################################################################################################################################################################### | 100%
setuptools 39.1.0: ############################################################################################################################################################################################### | 100%
openssl 1.0.2o: ################################################################################################################################################################################################## | 100%
pip 10.0.1: ###################################################################################################################################################################################################### | 100%
ca-certificates 2018.03.07: ###################################################################################################################################################################################### | 100%
Preparing transaction: done
Verifying transaction: done
Executing transaction: done
#
# To activate this environment, use:
# > source activate py27
#
# To deactivate an active environment, use:
# > source deactivate
#

➜ redundans git:(master) ✗ source activate py27

Example:

if you want to run fastqc for QC of fastq file:

from subprocess import Popen,PIPE,call

p=Popen(["fastqc","-f","fastq","-o", "/home/name/result/","/dev/stdin"],stdin=fopen("read.fastq","r") ,stdout=PIPE,stderr=PIPE)

print p.stderr

p.stdout.close()

More:

http://pymotw.com/2/subprocess/

Address of the bookmark: https://github.com/ventoy/Ventoy

Simple and efficient tools for data mining and data analysis
Accessible to everybody, and reusable in various contexts
Built on NumPy, SciPy, and matplotlib
Open source, commercially usable - BSD license

More at http://scikit-learn.org/stable/index.html

Address of the bookmark: http://scikit-learn.org/stable/auto_examples/index.html

More detail http://perlmaven.com/

Supported Perl Versions

Threaded Perl with a shared libperl  5.8, 5.10, 5.12, 5.14, 5.16

Supported Operating Systems

    MS Windows XP and later 32 and 64 bit.

    Linux 32 and 64 bit - minimum glibc 2.5, GTK+ 2.10, libstdc++6.

    Linux 32 bit  RHEL 3 and 4.

    Mac OSX 10.4 and 10.5 - ppc and i386.

    Mac OSX 10.6, 10.7, 10.8  - i386 and x86_64 ( 64 bit for Perl 5.16 only ).

Address of the bookmark: http://www.cavapackager.com/