% operator to format string can cause production risk

Count one violation each time a string use the % operator.

bad

print("%s is %s" % ("`$`", "fine"))

good

print("{0} is {1}, much {1}".format("format", "better"))

Why you should care

Future python version will promote usage of format().

If possible, prefer using the format() function to perform string-formatting instead of the % operator. The former provides more advanced options, allows you to reuse arguments in your string and removes ambiguity.

Business Impacts

Production Risk

CAST recommendations

References

https://www.quantifiedcode.com/knowledge-base/maintainability/Prefer%20%60format%28%29%60%20over%20string%20interpolation%20operator/4ACGxFj1

About CAST and Highlight’s Code Insights

Over the last 25 years, CAST has leveraged unique knowledge on software quality measurement by analyzing thousands of applications and billions of lines of code. Based on this experience and community standards on programming best practices, Highlight implements hundreds of code insights across 15+ technologies to calculate health factors of a software.

See features How it works