# import subprocess

**[import subprocess](https://docs.python.org/3/library/subprocess.html)** is a Python import that runs external programs and captures their output. Use `subprocess.run()` to execute commands from Python.

## Example

```python
# Python
# description: run external commands, capture output

import subprocess

# Run command and capture output
result = subprocess.run(["ls", "-la"], capture_output=True, text=True)
print(result.stdout)
print(f"Exit code: {result.returncode}")

# Run with input/output pipes
result = subprocess.run(["grep", "error"], input="line 1\nerror line\nline 3\n", 
                        capture_output=True, text=True)
print(result.stdout)

# Check if command succeeded
result = subprocess.run(["python", "--version"], capture_output=True, text=True)
if result.returncode == 0:
    print(f"Success: {result.stdout.strip()}")

# Run shell command (less secure, use with caution)
result = subprocess.run("ps aux | grep python", shell=True, capture_output=True, text=True)
print(result.stdout)
```

## Common functions

- `subprocess.run(args)`: run command and wait for completion
- `capture_output=True`: capture stdout and stderr
- `text=True`: return strings instead of bytes
- `input=...`: pass input to subprocess
- `check=True`: raise exception if command fails
- `cwd=...`: working directory for command
- `shell=True`: run through shell (less secure)
- `result.returncode`: exit code
- `result.stdout`, `result.stderr`: captured output