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module-import-not-at-top-of-file (E402)#

Derived from the pycodestyle linter.

What it does#

Checks for imports that are not at the top of the file. For Jupyter notebooks, this checks for imports that are not at the top of the cell.

Why is this bad?#

According to PEP 8, "imports are always put at the top of the file, just after any module comments and docstrings, and before module globals and constants."

This rule makes an exception for sys.path modifications, allowing for sys.path.insert, sys.path.append, and similar modifications between import statements.

In preview, this rule also allows os.environ modifications between import statements.

Example#

"One string"
"Two string"
a = 1
import os
from sys import x

Use instead:

import os
from sys import x

"One string"
"Two string"
a = 1