Maxi ContieriBe smart (and lazy) with low performant conditions
TL;DR: Premature Optimization is Evil. Optimization is Good.
Problems
- Low Performance
Solutions
- Sort the conditions from faster to slower
Context
Readability is always essential and you should avoid premature optimization.
Non-premature optimization happens when you have actual evidence you can improve your code execution time without much readability penalizations.
Sample Code
Wrong
def is_warm():
# This is a fast api call to your thermometer
response = requests.get
("https://iot-device-api.example.com/current_temperature")
temperature_data = response.json()
return temperature_data.get('temperature', 0) > 25
def is_weekend():
# This function checks if today is a weekend based on a slow calendar API call
response = requests.get
("https://calendar-api.example.com/today")
calendar_data = response.json()
return calendar_data.get('day_of_week', '').lower()
in ['saturday', 'sunday']
def is_sunny():
# Very slow function to a low performant weather API call
response = requests.get
("https://weather-api.example.com/current")
weather_data = response.json()
return weather_data.get('weather', '') == 'sunny'
is_sunny_value = is_sunny()
is_warm_value = is_warm()
is_weekend_value = is_weekend()
if is_sunny_value and is_warm_value and is_weekend_value:
# the 3 conditions are always evaluated
print("Let's go outside!")
else:
print("Stay at home.")
Right
if is_warm() and is_weekend() and is_sunny():
# the 3 conditions are evaluated in short circuit
# and sorted from fastest to slowest
# for a fast exit
print("Let's go outside!")
else:
print("Stay at home.")
Detection
[X] Semi-Automatic
You can detect slow calls using actual benchmarks.
Do not consider algorithm complexity since sometimes it is unrelated to actual data distribution. (for example, optimizing an array with a few elements).
Tags
- Performance
Conclusion
Find bottlenecks using Pareto rules.
Optimize your code-critical sections.
Relations
Disclaimer
Code Smells are my opinion.
Credits
Photo by Nick Abrams on Unsplash
The key to performance is elegance, not battalions of special cases.
Jon Bentley and Douglas McIlroy
This article is part of the CodeSmell Series.
