Autoformatting and documentation

.flake8

@@ -0,0 +1,14 @@
+[flake8]
+# Ignore style and complexity
+# E: style errors
+# W: style warnings
+# F401: module imported but unused
+# F811: redefinition of unused `name` from line `N`
+# F841: local variable assigned but never used
+ignore = E, C, W, F401, F403, F811, F841, E402, I100, I101, D400
+exclude =
+    helm-chart,
+    hooks,
+    setup.py,
+    statuspage,
+    versioneer.py

.gitignore

@@ -23,4 +23,3 @@ var/
 *.egg-info/
 .installed.cfg
 *.egg
-

.pre-commit-config.yaml

@@ -0,0 +1,21 @@
+repos:
+- repo: https://github.com/asottile/reorder_python_imports
+  rev: v1.3.5
+  hooks:
+  - id: reorder-python-imports
+    language_version: python3.6
+- repo: https://github.com/ambv/black
+  rev: 18.9b0
+  hooks:
+  - id: black
+- repo: https://github.com/pre-commit/pre-commit-hooks
+  rev: v2.1.0
+  hooks:
+  - id: end-of-file-fixer
+  - id: check-json
+  - id: check-yaml
+    exclude: ^helm-chart/nbviewer/templates/
+  - id: check-case-conflict
+  - id: check-executables-have-shebangs
+  - id: requirements-txt-fixer
+  - id: flake8

.travis.yml

@@ -0,0 +1,36 @@
+language: python
+
+python:
+- 3.7
+- 3.8
+
+before_install:
+- pip install --upgrade setuptools pip
+
+install:
+- pip install --editable .
+
+script:
+- python -m pytest -vvv nbresuse
+
+
+jobs:
+  include:
+    - name: autoformatting check
+      python: 3.6
+      # NOTE: It does not suffice to override to: null, [], or [""]. Travis will
+      #       fall back to the default if we do.
+      before_install: echo "Do nothing before install."
+      install: pip install pre-commit
+      script:
+        - pre-commit run --all-files
+      after_success: echo "Do nothing after success."
+      after_failure:
+        - |
+          echo "You can install pre-commit hooks to automatically run formatting"
+          echo "on each commit with:"
+          echo "    pre-commit install"
+          echo "or you can run by hand on staged files with"
+          echo "    pre-commit run"
+          echo "or after-the-fact on already committed files with"
+          echo "    pre-commit run --all-files"

CONTRIBUTING.md

@@ -1,6 +1,10 @@
 # Contributing
 
-Contributions to nbresuse are highly welcome!
+Contributions to NBResuse are highly welcome! As a [Jupyter](https://jupyter.org) project,
+you can follow the [Jupyter contributor guide](https://jupyter.readthedocs.io/en/latest/contributor/content-contributor.html).
+
+Make sure to also follow [Project Jupyter's Code of Conduct](https://github.com/jupyter/governance/blob/master/conduct/code_of_conduct.md)
+for a friendly and welcoming collaborative environment.
 
 ## Development set up
 
@@ -51,4 +55,38 @@ We recommend using [pipenv](https://docs.pipenv.org/) to make development easier
 
    ```bash
    MEM_LIMIT=$(expr 128 \* 1024 \* 1024) jupyter notebook
-   ```
+   ```
+
+8. NBResuse has adopted automatic code formatting so you shouldn't
+need to worry too much about your code style.
+As long as your code is valid,
+the pre-commit hook should take care of how it should look. Here is how to set up pre-commit hooks for automatic code formatting, etc.
+
+    ```bash
+    pre-commit install
+    ```
+
+    You can also invoke the pre-commit hook manually at any time with
+
+    ```bash
+    pre-commit run
+    ```
+
+which should run any autoformatting on your code
+and tell you about any errors it couldn't fix automatically.
+You may also install [black integration](https://github.com/ambv/black#editor-integration)
+into your text editor to format code automatically.
+
+If you have already committed files before setting up the pre-commit
+hook with `pre-commit install`, you can fix everything up using
+`pre-commit run --all-files`.  You need to make the fixing commit
+yourself after that.
+
+9. It's a good idea to write tests to exercise any new features,
+or that trigger any bugs that you have fixed to catch regressions. `pytest` is used to run the test suite. You can run the tests with:
+
+```bash
+python -m pytest -vvv nbresuse
+```
+
+in the repo directory.

README.md

@@ -1,14 +1,21 @@
-# nbresuse
+**[Installation](#installation)** |
+**[Configuration](#configuration)** |
+**[Resources Displayed](#resources-displayed)** |
+**[Contributing](#contributing)**
+
+# NBResuse
+
+[![PyPI](https://img.shields.io/pypi/v/nbresuse.svg)](https://pypi.python.org/pypi/nbresuse)
+[![PyPI](https://img.shields.io/pypi/l/nbresuse.svg)](https://pypi.python.org/pypi/nbresuse)
+[![GitHub](https://img.shields.io/badge/issue_tracking-github-blue?logo=github)](https://github.com/yuvipanda/nbresuse/issues)
+[![TravisCI build status](https://img.shields.io/travis/jupyter/nbviewer/master?logo=travis)](https://travis-ci.org/yuvipanda/nbresuse)
 [![Build Status](https://dev.azure.com/tpaine154/jupyter/_apis/build/status/timkpaine.nbresuse?branchName=master)](https://dev.azure.com/tpaine154/jupyter/_build/latest?definitionId=17&branchName=master)
 [![Coverage](https://img.shields.io/azure-devops/coverage/tpaine154/jupyter/17)](https://dev.azure.com/tpaine154/jupyter/_build?definitionId=17&_a=summary)
-[![PyPI](https://img.shields.io/pypi/l/nbresuse.svg)](https://pypi.python.org/pypi/nbresuse)
-[![PyPI](https://img.shields.io/pypi/v/nbresuse.svg)](https://pypi.python.org/pypi/nbresuse)
-
 
 
 ![Screenshot with memory limit](screenshot.png)
 
-NB Resource Usage (nbresuse) is a small extension for Jupyter Notebooks that
+NB Resource Usage (NBResuse) is a small extension for Jupyter Notebooks that
 displays an indication of how much resources your current notebook server and
 its children (kernels, terminals, etc) are using. This is displayed in the
 main toolbar in the notebook itself, refreshing every 5s.
@@ -80,9 +87,14 @@ As a command line argument:
 jupyter notebook --ResourceUseDisplay.track_cpu_percent=True
 ```
 
-## Resources displayed
+## Resources Displayed
 
-Currently it only displays Memory usage (just RSS). Other metrics will be
+Currently the server extension only reports memory usage (just RSS) and CPU usage. Other metrics will be
 added in the future as needed.
 
-The notebook extension currently doesn't show CPU usage.
+The notebook extension currently doesn't show CPU usage, only memory usage.
+
+## Contributing
+
+If you would like to contribute to the project, please read the [`CONTRIBUTING.md`](CONTRIBUTING.md). The `CONTRIBUTING.md` file
+explains how to set up a development installation and how to run the test suite.

nbresuse/__init__.py

@@ -1,7 +1,11 @@
 import os
 
 from tornado import ioloop
-from traitlets import Bool, Float, Int, Union, default
+from traitlets import Bool
+from traitlets import default
+from traitlets import Float
+from traitlets import Int
+from traitlets import Union
 from traitlets.config import Configurable
 
 from nbresuse.prometheus import PrometheusHandler
@@ -17,21 +21,21 @@ def _jupyter_server_extension_paths():
     """
     Set up the server extension for collecting metrics
     """
-    return [{
-        'module': 'nbresuse',
-    }]
+    return [{"module": "nbresuse"}]
 
 
 def _jupyter_nbextension_paths():
     """
     Set up the notebook extension for displaying metrics
     """
-    return [{
-        "section": "notebook",
-        "dest": "nbresuse",
-        "src": "static",
-        "require": "nbresuse/main"
-    }]
+    return [
+        {
+            "section": "notebook",
+            "dest": "nbresuse",
+            "src": "static",
+            "require": "nbresuse/main",
+        }
+    ]
 
 
 class ResourceUseDisplay(Configurable):
@@ -49,7 +53,7 @@ class ResourceUseDisplay(Configurable):
         we will start warning the user when they use (128 - (128 * 0.1)) MB.
 
         Set to 0 to disable warning.
-        """
+        """,
     ).tag(config=True)
 
     mem_limit = Union(
@@ -62,18 +66,18 @@ class ResourceUseDisplay(Configurable):
 
         Defaults to reading from the `MEM_LIMIT` environment variable. If
         set to 0, the max memory available is displayed.
-        """
+        """,
     ).tag(config=True)
 
-    @default('mem_limit')
+    @default("mem_limit")
     def _mem_limit_default(self):
-        return int(os.environ.get('MEM_LIMIT', 0))
+        return int(os.environ.get("MEM_LIMIT", 0))
 
     track_cpu_percent = Bool(
         default_value=False,
         help="""
         Set to True in order to enable reporting of CPU usage statistics.
-        """
+        """,
     ).tag(config=True)
 
     cpu_warning_threshold = Float(
@@ -86,7 +90,7 @@ def _mem_limit_default(self):
         we will start warning the user when they use (150 - (150 * 0.1)) %.
 
         Set to 0 to disable warning.
-        """
+        """,
     ).tag(config=True)
 
     cpu_limit = Float(
@@ -98,19 +102,19 @@ def _mem_limit_default(self):
 
         Defaults to reading from the `CPU_LIMIT` environment variable. If
         set to 0, the total CPU count available is displayed.
-        """
+        """,
     ).tag(config=True)
 
-    @default('cpu_limit')
+    @default("cpu_limit")
     def _cpu_limit_default(self):
-        return float(os.environ.get('CPU_LIMIT', 0))
+        return float(os.environ.get("CPU_LIMIT", 0))
 
 
 def load_jupyter_server_extension(nbapp):
     """
     Called during notebook start
     """
     resuseconfig = ResourceUseDisplay(parent=nbapp)
-    nbapp.web_app.settings['nbresuse_display_config'] = resuseconfig
+    nbapp.web_app.settings["nbresuse_display_config"] = resuseconfig
     callback = ioloop.PeriodicCallback(PrometheusHandler(nbapp), 1000)
     callback.start()

nbresuse/etc/nbextension.json

@@ -3,4 +3,3 @@
      "nbresuse/main": true
   }
 }
-

nbresuse/etc/serverextension.json

@@ -5,4 +5,3 @@
     }
   }
 }
-

nbresuse/metrics.py

@@ -20,10 +20,7 @@ def memory_metrics() -> MemoryMetrics:
     rss = sum([p.memory_info().rss for p in all_processes])
     virtual_memory = psutil.virtual_memory()
 
-    return MemoryMetrics(
-        rss,
-        virtual_memory.total
-    )
+    return MemoryMetrics(rss, virtual_memory.total)
 
 
 def cpu_metrics() -> CPUMetrics:
@@ -39,9 +36,7 @@ def get_cpu_percent(p):
         # about dead processes having no CPU usage
         except BaseException:
             return 0
+
     cpu_percent = sum([get_cpu_percent(p) for p in all_processes])
 
-    return CPUMetrics(
-        cpu_count * 100.0,
-        cpu_percent
-    )
+    return CPUMetrics(cpu_count * 100.0, cpu_percent)

nbresuse/prometheus.py

@@ -2,43 +2,30 @@
 from prometheus_client import Gauge
 from tornado import gen
 
-from nbresuse.metrics import CPUMetrics, MemoryMetrics, cpu_metrics, memory_metrics
+from nbresuse.metrics import cpu_metrics
+from nbresuse.metrics import CPUMetrics
+from nbresuse.metrics import memory_metrics
+from nbresuse.metrics import MemoryMetrics
 
 try:
     # Traitlets >= 4.3.3
     from traitlets import Callable
 except ImportError:
     from .utils import Callable
 
-TOTAL_MEMORY_USAGE = Gauge(
-    'total_memory_usage',
-    'counter for total memory usage',
-    []
-)
+TOTAL_MEMORY_USAGE = Gauge("total_memory_usage", "counter for total memory usage", [])
 
-MAX_MEMORY_USAGE = Gauge(
-    'max_memory_usage',
-    'counter for max memory usage',
-    []
-)
+MAX_MEMORY_USAGE = Gauge("max_memory_usage", "counter for max memory usage", [])
 
-TOTAL_CPU_USAGE = Gauge(
-    'total_cpu_usage',
-    'counter for total cpu usage',
-    []
-)
+TOTAL_CPU_USAGE = Gauge("total_cpu_usage", "counter for total cpu usage", [])
 
-MAX_CPU_USAGE = Gauge(
-    'max_cpu_usage',
-    'counter for max cpu usage',
-    []
-)
+MAX_CPU_USAGE = Gauge("max_cpu_usage", "counter for max cpu usage", [])
 
 
 class PrometheusHandler(Callable):
     def __init__(self, nbapp: NotebookApp):
         super().__init__()
-        self.config = nbapp.web_app.settings['nbresuse_display_config']
+        self.config = nbapp.web_app.settings["nbresuse_display_config"]
         self.session_manager = nbapp.session_manager
 
     @gen.coroutine