# Write to stdin
Source: [stackoverflow](https://stackoverflow.com/questions/8475290/how-do-i-write-to-a-python-subprocess-stdin)

```
subprocess.run(['cat'], input='foobar'.encode('utf-8'))
```
or
```
from subprocess import Popen, PIPE, STDOUT
p = Popen(['myapp'], stdout=PIPE, stdin=PIPE, stderr=PIPE)
stdout_data = p.communicate(input='data_to_write')[0]
```