As pointed out in #39, black inserts a space before a one-line or the summary in a multi-line docstring when it begins with a quote (") character. Default behavior for docformatter is to remove this space, which leads to a never-ending loop. The newly created argument --pre-summary-space will retain this black-inserted space at the expense of adding a space before every docstring, which black will then remove resulting in, yet again, a never-ending loop.

Add an argument (e.g., --black) to make docformatter only add the space when the line begins with a quote character when the --pre-summary-space argument is set. Thus, the invocation for black compatibility would be:

docformatter --pre-summary-space --black