consider-using-enumerate.md

Pattern: Use of range() and len() instead of enumerate()

Issue: -

Description

Emitted when code that iterates with range() and len() is encountered. Such code can be simplified by using the enumerate() built-in.

A common idiom to change every element of a list looks like this:

for i in range(len(L)):
    item = L[i]
    # ... compute some result based on item ...
    L[i] = result

This can be rewritten using enumerate() as:

for i, item in enumerate(L):
    # ... compute some result based on item ...
    L[i] = result

Further Reading

• PEP 279 - The enumerate() built-in function