Travis CI: Run black, doctest, flake8, mypy, and pytest (#964)

* Travis CI: Add type checking with mypy

* Create requirements.txt

* script: mypy --ignore-missing-stubs=cv2,numpy .

* Delete requirements.txt

* script: mypy --ignore-missing-imports .

* Run doctests

* Disable doctest -v other/detecting_english_programmatically.py

* Pytest

* No |

* pytest || true

* Run black doctest flake8 mypy pytest

* after_success: Build Directory.md

* Typo in filename: Dictionary.txt --> dictionary.txt'

Discovered via doctest run in #964

* python -m doctest -v

* pip install black flake8 mypy pytest

* pytest --doctest-glob='*.py'

* pytest --doctest-modules

* pytest --doctest-modules ./sorts

* pytest --doctest-modules ./ciphers ./other ./searches ./sorts ./strings || true

* if __name__ == "__main__":

* if __name__ == "__main__":

* if __name__ == '__main__':

* if __name__ == '__main__':

* if __name__ == '__main__':

* Create requirements.txt

* Update requirements.txt

* if __name__ == "__main__":

* Lose the doctests

* if __name__ == '__main__':

* Remove print-a-tuple

* doctest: Added missing spaces

* Update tabu_search.py

* The >>> are not doctests so change to >>)

* Travis CI: Run black, doctest, flake8, mypy, and pytest

* Link to the separate DIRECTORY.md file

* Update README.md

other/sierpinski_triangle.py

@@ -27,13 +27,6 @@ Credits: This code was written by editing the code from http://www.riannetrujill
 import turtle
 import sys
 PROGNAME = 'Sierpinski Triangle'
-if len(sys.argv) !=2: 
-    raise Exception('right format for using this script: $python fractals.py <int:depth_for_fractal>')
-
-myPen = turtle.Turtle()
-myPen.ht()
-myPen.speed(5)
-myPen.pencolor('red')
 
 points = [[-175,-125],[0,175],[175,-125]] #size of triangle
 
@@ -64,4 +57,12 @@ def triangle(points,depth):
                    depth-1)
 
 
-triangle(points,int(sys.argv[1]))
+if __name__ == '__main__':
+    if len(sys.argv) !=2: 
+        raise ValueError('right format for using this script: '
+                         '$python fractals.py <int:depth_for_fractal>')
+    myPen = turtle.Turtle()
+    myPen.ht()
+    myPen.speed(5)
+    myPen.pencolor('red')
+    triangle(points,int(sys.argv[1]))