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Find all installed modules

help("modules");

Virtual Environment

• How to Install and Manage Python Versions in Linux - Make Tech Easier

With virtualenv and virtualenvwrapper

# Installing virtualenv and virtualenvwrapper
sudo pip install virtualenv virtualenvwrapper

# Update the profile ~/.bashrc
# Add the  following lines

# virtualenv and virtualenvwrapper
export WORKON_HOME=$HOME/.virtualenvs
export VIRTUALENVWRAPPER_PYTHON=/usr/bin/python3
source /usr/local/bin/virtualenvwrapper.sh

# Reload the profile
source ~/.bashrc

# Creating python virtual environment
# The py3cv3 is a self-defined name 
mkvirtualenv py3cv3 -p python3

# Enter the specified virtual environment
workon py3cv3

# Exit the the specified virtual environment
deactivate

# List all of the environments.
lsvirtualenv

# Remove an environment
rmvirtualenv py3cv3

Timestamp

timestamp = datetime.datetime.now()
print("It is {}".format(timestamp.strftime("%A %d %B %Y %I:%M:%S%p")))

Math

total += 1

If-then

# Boolean, none
if motion is not None:
if not flag:

# Number
if delay > 0:
if delay == 0:
if total > frameCount:

# String
if "blue" in style:
if authors.startswith('['):
    authors = authors.lstrip('[').rstrip(']')
    
def doi_url(d): return f'http://{d}' if d.startswith('doi.org') else f'http://doi.org/{d}'