Notes for Effective Python

Reading notes for the book Effective Python: 90 Specific Ways to Write Better Python.

1. Pythonic thinking

Follow PEP style guide:

• Functions, variables, and attributes should be in lowercase_underscore format.
• Protected instance attributes should be in _leading_underscore format.
• Private instance attributes should be in __double_leading_underscore format.
• Classes (including exceptions) should be in CapitalizedWord format.
• Module-level constants should be in ALL_CAPS format.
• Instance methods in classes should use self, which refers to the object, as the name of the first parameter.
• Class methods should use cls, which refers to the class, as the name of the first parameter.

Expressions and Statement:

• Use inline negation: if a is not b
• Check for empty containers: if not somelist, don’t use if len(somelist)==0

Format:

• "{}={}".format(key, value)
• "{}={:.2f}".format(key, value)
• "{1}={0}".format(key, value)

Enumerate:

• enumerate(x, 1) starts counting from 1 instead of 0.
• for index, value in enumerate(x).
• The zip built-in function can be used to iterate over multiple iterators in parallel.
• zip truncates its output silently to the shortest iterator if you supply it with iterators of different lengths.
• Use the zip_longest function from the itertools built-in module if you want to use zip on iterators of unequal lengths without truncation.

2. Lists and Dictionaries

(To be continued)