# 8.13 `pipes` -- Interface to shell pipelines

Availability: Unix.

The `pipes` module defines a class to abstract the concept of a pipeline -- a sequence of convertors from one file to another.

Because the module uses /bin/sh command lines, a POSIX or compatible shell for `os.system()` and `os.popen()` is required.

The `pipes` module defines the following class:

`Template` ()
  An abstraction of a pipeline.

Example:

      >>> import pipes
      >>> t=pipes.Template()
      >>> t.append('tr a-z A-Z', '--')
      >>> f=t.open('/tmp/1', 'w')
      >>> f.write('hello world')
      >>> f.close()
      >>> open('/tmp/1').read()
      'HELLO WORLD'

- 8.13.1 Template Objects