step 8: add brain-progression game

Makefile

@@ -13,6 +13,9 @@ brain-calc:
 brain-gcd:
 	poetry run brain-gcd
 
+brain-progression:
+	poetry run brain-progression
+
 build:
 	poetry build
 

README.md

@@ -13,4 +13,8 @@
 
 
 #### Brain GCD Game
-[![GCD Game](https://asciinema.org/a/IPYSjBiw3zFSf9BOp4qr0P4dM.svg)](https://asciinema.org/a/IPYSjBiw3zFSf9BOp4qr0P4dM)
+[![GCD Game](https://asciinema.org/a/IPYSjBiw3zFSf9BOp4qr0P4dM.svg)](https://asciinema.org/a/IPYSjBiw3zFSf9BOp4qr0P4dM)
+
+
+#### Brain Progression Game
+[![Progression Game](https://asciinema.org/a/J4s6TNNnGl5zZfxwvF2PcnGzI.svg)](https://asciinema.org/a/J4s6TNNnGl5zZfxwvF2PcnGzI)

brain_games/scripts/brain_gcd.py

@@ -2,7 +2,7 @@
 import random
 from math import gcd
 from brain_games.cli import welcome_user
-from brain_games.utils import congrat_user, op_to_string
+from brain_games.utils import congrat_user
 
 
 def calc_game(name):

brain_games/scripts/brain_progression.py

@@ -0,0 +1,44 @@
+import prompt
+import random
+from math import gcd
+from brain_games.cli import welcome_user
+from brain_games.utils import congrat_user
+
+
+def calc_game(name):
+    print('What number is missing in the progression?')
+    correct = 0
+    while True:
+        n = random.randint(6, 12)
+        start = random.randint(1, 10)
+        step = random.randint(1, 7)
+        nums = list(range(start, start + n * step + 1, step))
+        skip = random.choice(range(n))
+        correct_answer = nums[skip]
+        nums[skip] = ".."
+        print(f"Question: {' '.join(map(str, nums))}")
+        try:
+            a_str = prompt.string("Your answer: ")
+            a = int(a_str)
+        except ValueError as e:
+            print(f"Got ValueError: {e}")
+            a = a_str
+        if a == correct_answer:
+            correct += 1
+            print("Correct!")
+        else:
+            print(f"'{a}' is wrong answer ;(. Correct answer was '{correct_answer}'.")
+            print(f"Let's try again, {name}!")
+            correct = 0
+        if correct == 3:
+            return True
+
+
+def main():
+    name = welcome_user()
+    if calc_game(name):
+        congrat_user(name)
+
+
+if __name__ == '__main__':
+    main()

pyproject.toml

@@ -17,6 +17,7 @@ brain-games = "brain_games.scripts.brain_games:main"
 brain-even = "brain_games.scripts.brain_even:main"
 brain-calc = "brain_games.scripts.brain_calc:main"
 brain-gcd = "brain_games.scripts.brain_gcd:main"
+brain-progression = "brain_games.scripts.brain_progression:main"
 
 
 [tool.poetry.group.dev.dependencies]