replace-stdout-stderr (UP022)

Derived from the pyupgrade linter.

Fix is sometimes available.

What it does

Checks for uses of subprocess.run that send stdout and stderr to a pipe.

Why is this bad?

As of Python 3.7, subprocess.run has a capture_output keyword argument that can be set to True to capture stdout and stderr outputs. This is equivalent to setting stdout and stderr to subprocess.PIPE , but is more explicit and readable.

Example

import subprocess
subprocess.run(["foo"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
Use instead:
import subprocess
subprocess.run(["foo"], capture_output=True)
References
Python 3.7 release notes
Python documentation: subprocess.run