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Add a sample presentation on Python virtual envs
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‎examples/presenter/py_virtual_envs.py

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from seleniumbase import BaseCase
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class PythonVirtualEnvPresentation(BaseCase):
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def test_py_virtual_envs(self):
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self.create_presentation(theme="serif", transition="slide")
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self.add_slide(
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'<h2>Python Virtual Environments:</h2><br />\n'
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'<h2>What, Why, and How</h2><hr /><br />\n'
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'\n'
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'<h3>Presented by <b>Michael Mintz</b></h3>')
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self.add_slide(
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'<p><b>About me:</b></p>\n'
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'<ul>'
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'<li>I created the <b>SeleniumBase</b> framework.</li>'
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"<li>I'm currently the DevOps Lead at <b>iboss</b>.</li>"
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'</ul>\n',
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image="https://seleniumbase.io/other/iboss_booth.png")
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self.add_slide(
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'<p><b>Topics & tools covered by this presentation:</b></p>'
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'<hr /><br />\n'
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'<ul>'
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'<li>Overview of Virtual Environments</li>'
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'<li>Python package management</li>'
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'<li>Python 3 "venv"</li>'
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'<li>virtualenv / virtualenvwrapper</li>'
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'<li>pip / "pip install"</li>'
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'<li>requirements.txt files</li>'
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'<li>setup.py files</li>'
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'</ul>')
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self.add_slide(
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'<p><b>Topics & tools that are NOT covered here:</b></p><hr />\n'
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'<br /><div><ul>'
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'<li>"conda"</li>'
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'<li>"pipenv"</li>'
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'<li>"poetry"</li>'
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'<li>"pipx"</li>'
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'</ul></div><br />'
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'<p>(Other Python package management tools)</p>')
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self.add_slide(
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'<p><b>What is a Python virtual environment?</b></p><hr /><br />\n'
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'<p>A Python virtual environment is a partitioned directory'
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' where a Python interpreter, libraries/packages, and scripts'
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' can be installed and isolated from those installed in other'
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' virtual environments or the global environment.</p>')
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self.add_slide(
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'<p><b>Why should we use Python virtual environments?</b>'
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'</p><hr /><br />\n'
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'<p>We should use Python virtual environments because different'
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' Python projects can have conflicting Python dependencies that'
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' cannot coexist in the same env.</p>')
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self.add_slide(
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'<p><b>Why? - continued</b></p><hr /><br />\n'
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'<p>Example: Project A and Project B both depend on'
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' different versions of the same Python library!</p>'
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'<p>Therefore, installing the second project requirements'
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' would overwrite the first one, causing it to break.</p>',
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code=(
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'# Project A requirement:\n'
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'urllib3==1.25.3\n\n'
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'# Project B requirement:\n'
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'urllib3==1.26.2'))
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self.add_slide(
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'<p><b>Why? - continued</b></p><hr /><br />\n'
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'<p>It is also possible that Project A and Project B'
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' require different versions of Python installed!</p>',
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code=(
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'# Project A requirement:\n'
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'Python-3.8\n\n'
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'# Project B requirement:\n'
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'Python-2.7'))
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self.add_slide(
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'<p><b>How do we create and use Python virtual envs?</b>'
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'</p><hr /><br />\n'
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'<div><b>There are tools/scripts we can use:</b></div><br />'
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'<ul>'
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'<li>The Python 3 "venv" command</li>'
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'<li>virtualenv / virtualenvwrapper</li>'
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'</ul>')
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self.add_slide(
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'<p><b>Python 3 "venv"</b></p><hr /><br />\n'
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'"venv" creates virtual environments in the location where run'
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' (generally with Python projects).',
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code=(
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'# Mac / Linux\n'
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'python3 -m venv ENV_NAME\n'
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'source ENV_NAME/bin/activate\n\n'
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'# Windows\n'
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'py -m venv ENV_NAME\n'
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'call ENV_NAME\\Scripts\\activate\n\n'
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'# (Type "deactivate" to leave a virtual environment.)'))
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self.add_slide(
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'<p><b>"mkvirtualenv" (from virtualenvwrapper)</b></p><hr />\n'
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'<br />"mkvirtualenv" creates virtual environments in one place'
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' (generally in your home directory).',
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code=(
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'# Mac / Linux\n'
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'python3 -m pip install virtualenvwrapper\n'
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'export WORKON_HOME=$HOME/.virtualenvs\n'
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'source `which virtualenvwrapper.sh`\n'
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'mkvirtualenv ENV_NAME\n\n'
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'# Windows\n'
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'py -m pip install virtualenvwrapper-win\n'
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'mkvirtualenv ENV_NAME\n\n'
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'# (Type "deactivate" to leave a virtual environment.)'))
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self.add_slide(
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'<p><b>List of commands from virtualenvwrapper</b></p>'
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'<hr /><br />',
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code=(
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'# Creating a virtual environment:\n'
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'mkvirtualenv ENV_NAME\n\n'
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'# Leaving your virtual environment:\n'
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'deactivate\n\n'
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'# Returning to a virtual environment:\n'
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'workon ENV_NAME\n\n'
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'# Listing all virtual environments:\n'
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'lsvirtualenv # OR "workon"\n\n'
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'# Deleting a virtual environment:\n'
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'rmvirtualenv ENV_NAME'))
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self.add_slide(
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'<p><b>Determining if you are in a virtual env</b></p>'
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'<hr /><br />'
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'<p>When activated, the name of your virtual env'
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' will appear in parentheses on the left side of your'
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' command prompt.</p>',
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code=(
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'# Example of how it may look on a Windows machine:\n'
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'C:\\Users\\Michael\\github> mkvirtualenv my_env\n'
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'(my_env) C:\\Users\\Michael\\github>'))
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self.add_slide(
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'<p><b>Installing packages with "pip install"</b></p><hr /><br />'
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'<p>Once you have created a Python virtual environment and are'
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' inside, it is now safe to install packages from PyPI,'
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' setup.py files, and/or requirements.txt files.</p>\n',
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code=(
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'# Install a package from PyPI:\n'
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'pip install seleniumbase\n\n'
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'# Install packages from a folder with setup.py:\n'
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'pip install . # Normal installation\n'
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'pip install -e . # Editable install\n\n'
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'# Install packages from a requirements.txt file:\n'
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'pip install -r requirements.txt\n'))
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self.add_slide(
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'<p><b>Other useful "pip" commands</b></p><hr /><br />',
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code=(
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'# See which Python packages are installed:\n'
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'pip list\n\n'
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'# See which installed Python packages are outdated:\n'
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'pip list --outdated\n\n'
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'# Create a requirements file from installed packages:\n'
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'pip freeze > my_requirements.txt'))
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self.add_slide(
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'<br /><br /><h2><b>Live Demo Time!</b></h2><hr /><br />',
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image="https://seleniumbase.io/other/python_3d_logo.png")
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self.add_slide(
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'<h2><b>The End. Questions?</b></h2><hr /><br />\n'
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'<h3>Where to find me:</h3>'
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'<ul>'
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'<li><a href="https://github.com/mdmintz">'
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'https://github.com/mdmintz</a></li>'
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'<li><a href="https://github.com/seleniumbase/SeleniumBase">'
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'https://github.com/seleniumbase/SeleniumBase</a></li>'
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'<li><a href="https://seleniumbase.io/">'
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'https://seleniumbase.io/</a></li>'
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'</ul>')
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self.begin_presentation(
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filename="py_virtual_envs.html", show_notes=False, interval=0)

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