string-dot-format-mixing-automatic (F525)

Derived from the Pyflakes linter.

What it does

Checks for str.format calls that mix automatic and manual numbering.

Why is this bad?

In str.format calls, mixing automatic and manual numbering will raise a ValueError at runtime.

Example

"{0}, {}".format("Hello", "World")

Use instead:

"{0}, {1}".format("Hello", "World")

Or:

"{}, {}".format("Hello", "World")

References

• Python documentation: str.format