Yes. In Prefect 3.x you can run PowerShell from Python in a few ways. Quick options - Use Prefect’s shell utility flow:

prefect.cli.shell.run_shell_process

(logs output, raises on non‑zero, supports env/cwd via

popen_kwargs

) - If you need to capture stdout/stderr as return values inside your flow code, use Python’s

subprocess

in a

@task

- For deployment build/pull steps (prefect.yaml), use the

run_shell_script

step which returns stdout/stderr Examples 1) Run a .ps1 file from a flow with Prefect’s shell utility (logs output)

from prefect import flow
from prefect.cli.shell import run_shell_process
import os

@flow
def run_ps():
    run_shell_process(
        command='powershell -NoProfile -ExecutionPolicy Bypass -File ".\\script.ps1" -Arg1 value',
        log_output=True,
        stream_stdout=True,  # stream live stdout to Prefect logs
        popen_kwargs={
            "cwd": r"C:\path\to\dir",
            "env": {**os.environ, "MY_VAR": "123"},
        },
    )

if __name__ == "__main__":
    run_ps()

Notes: -

run_shell_process

does not return stdout/stderr; it logs them. It raises on non-zero exit (Prefect

FailedRun

). -

popen_kwargs

supports standard

subprocess.Popen

args like

env

and

cwd

. 2) Capture output programmatically in a task

from prefect import flow, task
import subprocess, os

@task
def run_powershell_capture(cmd: str):
    r = subprocess.run(
        cmd,
        shell=True,          # ok on Windows to use PowerShell/cmd pipelines
        text=True,
        capture_output=True,
        cwd=r"C:\path\to\dir",
        env={**os.environ, "MY_VAR":"123"},
    )
    if r.returncode != 0:
        raise RuntimeError(f"PowerShell failed: {r.stderr}")
    return r.stdout

@flow
def my_flow():
    out = run_powershell_capture('powershell -NoProfile -Command "Get-Date"')
    print(out)

if __name__ == "__main__":
    my_flow()

3) If you’re configuring deployments (prefect.yaml), and want stdout/stderr back

build:
  - prefect.deployments.steps.run_shell_script:
      id: setup
      script: powershell -NoProfile -ExecutionPolicy Bypass -Command "Write-Output 'Hello from PS'"
      directory: C:\path\to\dir
      env:
        MY_VAR: "123"
      stream_output: true

- This step returns both

stdout

and

stderr

that can be referenced by subsequent steps (e.g.,

{{ setup.stdout }}

) and fails on non-zero exit. Gotchas and tips - On Windows, the default shell is cmd.exe; explicitly invoke PowerShell:

powershell ...

or

pwsh ...

(for PowerShell 7+). If you need PS7 features cross‑platform, use

pwsh

. - Execution policy can block .ps1 files. Common fixes:

-ExecutionPolicy Bypass

or set it per-process:

Set-ExecutionPolicy -Scope Process -ExecutionPolicy Bypass -Force

. - For pipelines/redirection, keep

shell=True

(Prefect’s

run_shell_process

already does this). With

subprocess.run

, specify it yourself. - Encoding: if you see odd characters, set output encoding in PowerShell:

[Console]::OutputEncoding = [System.Text.UTF8Encoding]::new()

. If you can share whether you need to capture stdout/stderr in Python and whether you’re on Windows PowerShell 5.1 or PowerShell 7 (

pwsh

), I can tailor the snippet further.