Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

List Comprehension¶

Notice that a walrus expression in a list comprehension must be in included in parentheses (to avoid ambiguitions).

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Tips and Traps¶

1. The finally statements are guaranteed to be executed (presuming no power outage or anything outside of Python's control) after a try/except block runs even if return, break

Tips and Traps¶

1. If you need trackback information when throwing an exception use raise ExceptionClass(msg), otherwise, use sys.exit(msg) instead.

2. The assert statement (which raises AssertionError if the assertion is not met) is a very good way to ensure conditions to be met.

    :::python
    assert some_condition

Tips and Traps¶

1. Prefer Dataclass to namedtuple for many reasons.

   • A namedtuple is immutable while a dataclass can be both mutable (frozen=False which is the default) or immutable (frozen=True).

     However, namedtuple does have one advantage over dataclass. Members of a namedtuple is assible both via the dot operator and index. In situations where both dot accessing and index accessing of members is required, a namedtuple comes handy. For examples, a list of namedtuple objects can be used as the data for creating a pandas DataFrame but not a list of dataclass objects.