recognize it was safe to do so, put it there manually and *Black* will
keep it.
+
### Strings
*Black* prefers double quotes (`"` and `"""`) over single quotes (`'`
key. My recommendation here is to keep using whatever is faster to type
and let *Black* handle the transformation.
+
### Line Breaks & Binary Operators
*Black* will break a line before a binary operator when splitting a block
style guide enforcement tools like Flake8. Since ``W503`` is not PEP 8 compliant,
you should tell Flake8 to ignore these warnings.
+
### Slices
PEP 8 [recommends](https://www.python.org/dev/peps/pep-0008/#whitespace-in-expressions-and-statements)
enforcement tools like Flake8. Since ``E203`` is not PEP 8 compliant, you should
tell Flake8 to ignore these warnings.
+
### Parentheses
Some parentheses are optional in the Python grammar. Any expression can
In those cases, parentheses are removed when the entire statement fits
in one line, or if the inner expression doesn't have any delimiters to
-further split on. Otherwise, the parentheses are always added.
+further split on. If there is only a single delimiter and the expression
+starts or ends with a bracket, the parenthesis can also be successfully
+omitted since the existing bracket pair will organize the expression
+neatly anyway. Otherwise, the parentheses are added.
+
+Please note that *Black* does not add or remove any additional nested
+parentheses that you might want to have for clarity or further
+code organization. For example those parentheses are not going to be
+removed:
+```py3
+return not (this or that)
+decision = (maybe.this() and values > 0) or (maybe.that() and values < 0)
+```
+
### Call chains
as a [fluent interface](https://en.wikipedia.org/wiki/Fluent_interface).
*Black* formats those treating dots that follow a call or an indexing
operation like a very low priority delimiter. It's easier to show the
-behavior than to explain it. Look at the example::
+behavior than to explain it. Look at the example:
```py3
def example(session):
result = (
)
```
+
### Typing stub files
PEP 484 describes the syntax for type hints in Python. One of the
Use [joslarson.black-vscode](https://marketplace.visualstudio.com/items?itemName=joslarson.black-vscode).
+
### SublimeText 3
Use [sublack plugin](https://github.com/jgirardet/sublack).
+
### IPython Notebook Magic
Use [blackcellmagic](https://github.com/csurfer/blackcellmagic).
+
### Other editors
Atom/Nuclide integration is planned by the author, others will
* fixed non-deterministic formatting when multiple pairs of removable parentheses
were used (#183)
+* fixed multiline strings being unnecessarily wrapped in optional
+ parentheses in long assignments (#215)
+
* fixed not splitting long from-imports with only a single name
* fixed Python 3.6+ file discovery by also looking at function calls with