40th Week of 2021

Coding⚑

Python⚑

Click⚑

• New: Invoke other commands from a command.

  This is a pattern that is generally discouraged with Click, but possible nonetheless. For this, you can use the Context.invoke() or Context.forward() methods.

Optimization⚑

• New: Add tips on how to optimize your python command line tools.

  • Minimize the relative import statements on command line tools:

    When developing a library, it's common to expose the main objects into the package __init__.py under the variable __all__. The problem with command line programs is that each time you run the command it will load those objects, which can mean an increase of 0.5s or even a second for each command, which is unacceptable. * Don't dynamically install the package:

    If you install the package with pip install -e . you will see an increase on the load time of ~0.2s. It is useful to develop the package, but when you use it, do so from a virtualenv that installs it directly without the -e flag.

Python Snippets⚑

• New: Check if a dictionary is a subset of another.

  If you have two dictionaries big = {'a': 1, 'b': 2, 'c':3} and small = {'c': 3, 'a': 1}, and want to check whether small is a subset of big, use the next snippet:

  >>> small.items() <= big.items()
  True
  

• Correction: Group or sort a list of dictionaries or objects by a specific key.

  Improve previous method with the concepts learned from the official docs

  Particularly improve the sorting by multiple keys with the next function:

  >>> def multisort(xs, specs):
      for key, reverse in reversed(specs):
          xs.sort(key=attrgetter(key), reverse=reverse)
      return xs
  
  >>> multisort(list(student_objects), (('grade', True), ('age', False)))
  [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]
  

Pydantic⚑

• New: Copy produces copy that modifies the original.

  When copying a model, changing the value of an attribute on the copy updates the value of the attribute on the original. This only happens if deep != True. To fix it use: model.copy(deep=True).

DevOps⚑

Continuous Integration⚑

Flakehell⚑

• New: Troubleshoot the 'Namespace' object has no attribute 'extended_default_ignore' error.

  Add to your pyproject.toml:

  [tool.flakeheaven]
  extended_default_ignore=[]
  

Dependency managers⚑

• New: Sync the virtualenv libraries with the requirements files.

  python -m piptools sync requirements.txt requirements-dev.txt
  

• Correction: Use -c instead of -r in the nested requirement files.

  To avoid duplication of version pins.

Operative Systems⚑

Linux⚑

Kitty⚑

• New: Introduce kitty the terminal emulator.

  kitty is a fast, feature-rich, GPU based terminal emulator written in C and Python with nice features for the keyboard driven humans like me.