When a function produces closely related results, return them together instead of creating separate functions for each result. Python packages comma-separated return expressions into one tuple object, which can then be unpacked into individual variables. section 6.2.2 section 6.2.3
Listing 6.4 Returning multiple values from a function
from statistics import mean, stdev def generate_stats(measures): measure_mean = mean(measures) measure_std = stdev(measures) return measure_mean, measure_std
Return the mean and standard deviation together when both values describe the same measurements. section 6.2.2
Listing 6.5 Unpacking the return tuple object
m_mean, m_std = generate_stats(measures)
print(f"Mean: {m_mean}; SD: {m_std}")
# output: Mean: 5.6; SD: 0.8786353054595518
Unpack the returned tuple directly when both results are needed. section 6.2.3
Choose the return shape according to how the results relate:
- Return related results together, such as a mean and standard deviation describing the same measurements. section 6.2.2
- Split unrelated operations into separate functions; combining unrelated formatted data and calculations makes the interface harder to understand. section 6.2.2
- Use tuple unpacking for concise access to individual returned items, or retain the tuple when treating the result as one object. section 6.2.3
