Pythonic Programming

1. Links

1.1. Code Like a Pythonista

1.2. Idioms and Anti-Idioms in Python

1.3. Python Idioms and Efficiency Suggestions

2. Syntax

2.1. use parenthesis for long-line wrapping

2.2. use r"C:\temp.txt" for raw strings

2.2.1. Backslashes not interpreted as escapes

2.2.2. ideal for Windows file paths

2.3. use "".join(list) to join a list of strings

2.3.1. add spaces or commas as needed

2.3.1.1. " ".join(list)

2.3.1.2. ", ".join(list)

2.3.2. use generator functions

2.3.2.1. "".join(fn(i) for i in items)

2.4. use collections.defaultdict() to create dictionaries with default factory functions

2.5. use locals() for named string formatting

2.6. Use a list comprehension when a computed list is the desired end result.

2.6.1. [n ** 2 for n in range(10) if n % 2]

2.6.2. all values calculated at once

2.6.3. greedy evaluation

2.7. Use a generator expression when the computed list is just an intermediate step.

2.7.1. values calculated as needed

2.8. use lists instead of concatenating strings using the "+=" operator.

2.8.1. huge memory saver

2.8.2. huge speed improvement

2.8.3. can be joined before output