1 16-TypeFormatDebug

Previous: 15-ClassesInheritance.html

1.1 Screencasts

• Password for the Vimeo videos is in Zulip chat.
• https://vimeo.com/526304166
• Tip: If anyone want to speed up the lecture videos a little, inspect the page, go to the browser console, and paste this in:
  document.querySelector('video').playbackRate = 1.2

1.2 Demo a common scenario in the VM

• You’ve just downloaded some code you don’t know.
• You want to understand it, edit it, and improve it, or fix it.
• Where to start?
• How to learn it quickly?
• Files for the day include:
  • 16-TypeFormatDebug/sonar_original.py (taken from here: http://inventwithpython.com/invent4thed/chapter13.html)
  • 16-TypeFormatDebug/monkey_wrapper.py
  • 16-TypeFormatDebug/sonar_improved.py
• Today, we’ll clean up the original code above, reveal errors, bugs, etc., through automated assistance.

1.2.1 1. Review of code styling and how to auto-style

• Review 03-IntroPython section on code formatting.
• Watch the video linked there today!

#!/bin/bash

# Install once.
sudo zypper/dnf/apt install python3-black
# or
pip3 install --upgrade black --user

# Run whenever
black sonar_improved.py
# or
black *.py

+++++++++++ Cahoot-16-1
https://mst.instructure.com/courses/58101/quizzes/56633

1.2.2 2. Review of type-hinting and how to auto-hint

• Review 11-TypeHints and how to auto-hint.

#!/bin/bash

# Install once
sudo zypper/dnf/apt install mypy python3-mypy
pip3 install --upgrade monkeytype mypy --user

# Show files above
vim sonar_improved.py sonar_original.py monkey_wrapper.py
monkeytype run monkey_wrapper.py
monkeytype apply sonar_improved.py

1.2.3 3. Interpreters, shebangs, and file permissions

• ipython versus python
• How to give a file executable permissions?
• What is a shebang?

#!/bin/bash

# Install once
sudo zypper/dnf/apt install python3-ipython

ipython3

# Run whenever
vim sonar_improved.py
# Introduce error?
ipython3 sonar_improved.py
# Fix the error

ll sonar_improved
chmod -x sonar_improved.py
ll
./sonar_improved.py
chmod +x sonar_improved.py

# Show the shebang

1.2.4 4. Review of interactive debuggers and how to use them

• Review 03-IntroPython section on debuggers and how to use them.
  • pudb: https://documen.tician.de/pudb/starting.html
  • spyder: https://www.spyder-ide.org/
    ``` {.sh .numberLines}
    #!/bin/bash

2 Install once

sudo zypper/dnf/apt install python3-pudb python3-spyder
pip3 install –upgrade pudb spyder –user

3 Run whenever

pudb sonar_improved.py
spyder3 sonar_improved.py &

+++++++++++ Cahoot-16-2
https://mst.instructure.com/courses/58101/quizzes/56634

### 5. Review of linting and how to use tips
https://pylint.org
``` {.sh .numberLines}
#!/bin/bash

# Install once
sudo zypper/dnf/apt install python3-pylint python3-spyder
pip3 install --upgrade pylint spyder --user
# Install linting additions to your favorite text editor (optional)

# Run whenever
pylint sonar_improved.py
vim sonar_improved.py
spyder3 sonar_improved.py &

+++++++++++ Cahoot-16-3
https://mst.instructure.com/courses/58101/quizzes/56635

3.0.1 6. Review of diff tools and how to use them

• https://meldmerge.org/

#!/bin/bash

sudo zypper/apt/dnf install meld

man meld
meld --diff sonar_original.py sonar_improved.py

man vimdiff
vim -d sonar_original.py sonar_improved.py

man diff
diff -y --color sonar_original.py sonar_improved.py

git init
git add .
git commit -m "init"
cp sonar_improved.py sonar_original.py
git diff sonar_improved.py

3.0.2 7. Tools to complement documenting your code

Control flow graph: https://en.wikipedia.org/wiki/Control-flow_graph
* py2cfg
* https://py2cfg.readthedocs.io/en/latest/
* https://gitlab.com/classroomcode/py2cfg
* https://pypi.org/project/py2cfg/

#!/bin/bash

pip3 install py2cfg --user

py2cfg sonar_improved.py
ls

Calls: https://en.wikipedia.org/wiki/Call_graph
* pycallgraph
* https://pycallgraph.readthedocs.io/en/master/
* https://pypi.org/project/pycallgraph/
* https://github.com/gak/pycallgraph

#!/bin/bash

pip3 install pycallgraph --user

pycallgraph graphviz sonar_improved.py
ls

UML class diagram: https://en.wikipedia.org/wiki/Class_diagram
* https://pylint.org
* Contains pyreverse
* http://epydoc.sourceforge.net/
* https://modeling-languages.com/uml-tools/#python
* https://sungsoo.github.io/2018/03/21/uml-tools-for-python.html
* https://pynsource.com/

#!/bin/bash

sudo zypper/dnf/apt install python3-pylint
# or
pip3 install pylint --user

pyreverse -o svg somethingwithclasses.py
ls

See 15-ClassesInheritance for examples.

Text documentation generation?
* https://wiki.python.org/moin/DocumentationTools
* https://docs.readthedocs.io/en/stable/intro/getting-started-with-sphinx.html

#!/bin/bash

# TODO sometime later?

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