Python with as a Function

Use context managers with a function instead of a statement.

Provides a minimal and portable interface for using context managers with all the advantages of functions over syntax.

Allows using context managers on Python implementations that are too old or too incomplete to have the with statement.

Versioning

This library's version numbers follow the SemVer 2.0.0 specification.

Installation

pip install with-as-a-function

Usage

Import with_, iwith, or both:

from with_ import with_, iwith

with_ wraps a function in a context manager. For example,

data = with_(open('my_file.txt'), lambda my_file: my_file.read())

is similar to:

with open('my_file.txt') as my_file:
    data = my_file.read()

iwith wraps a generator or other iterable in a context manager. For example,

lines = iwith(open('my_file.txt'), lambda my_file: my_file)

is similar to:

def _lines():
    with open('my_file.txt') as my_file:
        yield from my_file
lines = _lines()

And of course because with_ and iwith are functions, you can combine them with functools.partial and other functional programming libraries and techniques for many more uses.

Portability

Portable to all releases of Python 3, and releases of Python 2 starting with 2.2.

Even those without the with statement and without the yield from expression.

For popular Python reimplementations with quirks or bugs that make the normal implementation of this module not work, other implementations are included in the source distribution.