This metric measures the number of modules that are directly imported by each module (file). Modules that import many other modules often have too many responsibilities and are not well-focused. This makes it difficult to understand and maintain the module.

Split and/or refactor files with too many responsibilities to create modules with a single, well-defined role.

Python Language Reference: The import statement.

M. Fowler, Refactoring. Addison-Wesley, 1999.

Wikipedia: Code refactoring.