Merge branch 'master' into Upgrade-to-Python-3.8

Author: cclauss

.coveragerc

@@ -0,0 +1,4 @@
+[report]
+sort = Cover
+omit =
+    .env/*

.github/workflows/autoblack.yml

@@ -0,0 +1,24 @@
+# GitHub Action that uses Black to reformat Python code (if needed) when doing a git push.
+# If all Python code in the repo is compliant with Black then this Action does nothing.
+# Otherwise, Black is run and its changes are committed to the repo.
+# https://github.com/cclauss/autoblack
+
+name: autoblack_push
+on: [push]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions/setup-python@v1
+      - run: pip install black
+      - run: black --check .
+      - name: If needed, commit black changes to a new pull request
+        if: failure()
+        run: |
+          black .
+          git config --global user.name github-actions
+          git config --global user.email '${GITHUB_ACTOR}@users.noreply.github.com'          
+          git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/$GITHUB_REPOSITORY
+          git commit -am "fixup! Format Python code with psf/black push"
+          git push --force origin HEAD:$GITHUB_REF

.github/workflows/directory_writer.yml

@@ -0,0 +1,20 @@
+# The objective of this GitHub Action is to update the DIRECTORY.md file (if needed)
+# when doing a git push
+name: directory_writer
+on: [push]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v1
+        with:
+          python-version: 3.x
+      - name: Update DIRECTORY.md
+        run: |
+          scripts/build_directory_md.py 2>&1 | tee DIRECTORY.md
+          git config --global user.name github-actions
+          git config --global user.email '${GITHUB_ACTOR}@users.noreply.github.com'
+          git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/$GITHUB_REPOSITORY
+          git commit -am "updating DIRECTORY.md" ||  true
+          git push --force origin HEAD:$GITHUB_REF || true

.github/workflows/stale.yml

@@ -0,0 +1,15 @@
+name: Mark stale issues and pull requests
+on:
+  schedule:
+  - cron: "0 0 * * *"
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/stale@v1
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        stale-issue-message: 'Stale issue message'
+        stale-pr-message: 'Stale pull request message'
+        stale-issue-label: 'no-issue-activity'
+        stale-pr-label: 'no-pr-activity'

.travis.yml

@@ -5,11 +5,11 @@ before_install: pip install --upgrade pip setuptools
 install: pip install -r requirements.txt
 before_script:
   - black --check . || true
-  - flake8 . --count --select=E9,F4,F63,F7,F82 --show-source --statistics
+  - flake8 . --count --select=E101,E9,F4,F63,F7,F82,W191 --show-source --statistics
+  - flake8 . --count --exit-zero --max-line-length=127 --statistics
 script:
   - scripts/validate_filenames.py  # no uppercase, no spaces, in a directory
   - mypy --ignore-missing-imports .
-  - pytest . --doctest-modules
+  - pytest --doctest-modules --cov-report=term-missing:skip-covered --cov=. .
 after_success:
-  - scripts/build_directory_md.py > DIRECTORY.md
-  - cat DIRECTORY.md
+  - scripts/build_directory_md.py 2>&1 | tee DIRECTORY.md

CONTRIBUTING.md

@@ -30,25 +30,32 @@ Your contribution will be tested by our [automated testing on Travis CI](https:/
 We want your work to be readable by others; therefore, we encourage you to note the following:
 
 - Please write in Python 3.7+.  __print()__ is a function in Python 3 so __print "Hello"__ will _not_ work but __print("Hello")__ will.
-
 - Please focus hard on naming of functions, classes, and variables.  Help your reader by using __descriptive names__ that can help you to remove redundant comments.
-    - Single letter variable names are _old school_ so please avoid them unless their life only spans a few lines.
-    - Expand acronyms because __gcd()__ is hard to understand but __greatest_common_divisor()__ is not.
-    - Please follow the [Python Naming Conventions](https://pep8.org/#prescriptive-naming-conventions) so variable_names and function_names should be lower_case, CONSTANTS in UPPERCASE, ClassNames should be CamelCase, etc.
+  - Single letter variable names are _old school_ so please avoid them unless their life only spans a few lines.
+  - Expand acronyms because __gcd()__ is hard to understand but __greatest_common_divisor()__ is not.
+  - Please follow the [Python Naming Conventions](https://pep8.org/#prescriptive-naming-conventions) so variable_names and function_names should be lower_case, CONSTANTS in UPPERCASE, ClassNames should be CamelCase, etc.
+
+
 
 - We encourage the use of Python [f-strings](https://realpython.com/python-f-strings/#f-strings-a-new-and-improved-way-to-format-strings-in-python) where the make the code easier to read.
 
-- Please consider running [__psf/black__](https://github.com/python/black) on your Python file(s) before submitting your pull request.  This is not yet a requirement but it does make your code more readable and automatically aligns it with much of [PEP 8](https://www.python.org/dev/peps/pep-0008/).  There are other code formatters (autopep8, yapf) but the __black__ style is now the recommendation of the Python Core Team. To use it,
-    ```bash
-    pip3 install black  # only required the first time
-    black .
-    ```
+
+
+- Please consider running [__psf/black__](https://github.com/python/black) on your Python file(s) before submitting your pull request.  This is not yet a requirement but it does make your code more readable and automatically aligns it with much of [PEP 8](https://www.python.org/dev/peps/pep-0008/). There are other code formatters (autopep8, yapf) but the __black__ style is now the recommendation of the Python Core Team. To use it,
+
+  ```bash
+  pip3 install black  # only required the first time
+  black .
+  ```
 
 - All submissions will need to pass the test __flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics__ before they will be accepted so if possible, try this test locally on your Python file(s) before submitting your pull request.
-    ```bash
-    pip3 install flake8  # only required the first time
-    flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
-    ```
+
+  ```bash
+  pip3 install flake8  # only required the first time
+  flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+  ```
+
+
 
 - Original code submission require docstrings or comments to describe your work.
 
@@ -93,9 +100,10 @@ We want your work to be readable by others; therefore, we encourage you to note
   ```
 
   These doctests will be run by pytest as part of our automated testing so please try to run your doctests locally and make sure that they are found and pass:
-    ```bash
-    python3 -m doctest -v my_submission.py
-    ```
+
+  ```bash
+  python3 -m doctest -v my_submission.py
+  ```
 
   The use of the Python builtin __input()__ function is **not** encouraged:
 
@@ -110,44 +118,43 @@ We want your work to be readable by others; therefore, we encourage you to note
   ```python
   starting_value = int(input("Please enter a starting value: ").strip())
   ```
-  
+
   The use of [Python type hints](https://docs.python.org/3/library/typing.html) is encouraged for function parameters and return values.  Our automated testing will run [mypy](http://mypy-lang.org) so run that locally before making your submission.
-```python
-def sumab(a: int, b: int) --> int:
+
+  ```python
+  def sumab(a: int, b: int) --> int:
     pass
   ```
 
-- [__list comprehensions and generators__](https://docs.python.org/3/tutorial/datastructures.html#list-comprehensions) are preferred over the use of `lambda`, `map`, `filter`, `reduce` but the important thing is to demonstrate the power of Python in code that is easy to read and maintain.
 
-- Avoid importing external libraries for basic algorithms. Only use those libraries for complicated algorithms.
 
+- [__List comprehensions and generators__](https://docs.python.org/3/tutorial/datastructures.html#list-comprehensions) are preferred over the use of `lambda`, `map`, `filter`, `reduce` but the important thing is to demonstrate the power of Python in code that is easy to read and maintain.
+
+
+
+- Avoid importing external libraries for basic algorithms. Only use those libraries for complicated algorithms.
 - If you need a third party module that is not in the file __requirements.txt__, please add it to that file as part of your submission.
 
 #### Other Standard While Submitting Your Work
 
 - File extension for code should be `.py`. Jupiter notebook files are acceptable in machine learning algorithms.
-
-- Please avoid creating new directories if at all possible.  Try to fit your work into the existing directory structue.
-
 - Strictly use snake_case (underscore_separated) in your file_name, as it will be easy to parse in future using scripts.
+- Please avoid creating new directories if at all possible. Try to fit your work into the existing directory structure.
+- If possible, follow the standard *within* the folder you are submitting to.
 
-  If possible, follow the standard *within* the folder you are submitting to.
 
-- If you have modified/added code work, make sure the code compiles before submitting.
 
+- If you have modified/added code work, make sure the code compiles before submitting.
 - If you have modified/added documentation work, ensure your language is concise and contains no grammar errors.
-
 - Do not update the README.md or DIRECTORY.md file which will be periodically autogenerated by our Travis CI processes.
-
 - Add a corresponding explanation to [Algorithms-Explanation](https://github.com/TheAlgorithms/Algorithms-Explanation) (Optional but recommended).
-
 - All submissions will be tested with [__mypy__](http://www.mypy-lang.org) so we encourage to add [__Python type hints__](https://docs.python.org/3/library/typing.html) where it makes sense to do so.
 
-- Most importantly,
 
+
+- Most importantly,
   - **Be consistent in the use of these guidelines when submitting.**
   - **Join** [Gitter](https://gitter.im/TheAlgorithms) **now!**
   - Happy coding!
 
-
 Writer [@poyea](https://github.com/poyea), Jun 2019.