complete draft: update from Atlas

Author: ramalho

13-protocol-abc/lotto.py

@@ -5,7 +5,7 @@
 from tombola import Tombola
 
 
-class LotteryBlower(Tombola):
+class LottoBlower(Tombola):
 
     def __init__(self, iterable):
         self._balls = list(iterable)  # <1>
@@ -17,14 +17,14 @@ def pick(self):
         try:
             position = random.randrange(len(self._balls))  # <2>
         except ValueError:
-            raise LookupError('pick from empty BingoCage')
+            raise LookupError('pick from empty LottoBlower')
         return self._balls.pop(position)  # <3>
 
     def loaded(self):  # <4>
         return bool(self._balls)
 
     def inspect(self):  # <5>
-        return tuple(sorted(self._balls))
+        return tuple(self._balls)
 
 
 # end::LOTTERY_BLOWER[]

13-protocol-abc/tombola.py

@@ -28,7 +28,7 @@ def inspect(self):
             except LookupError:
                 break
         self.load(items)  # <7>
-        return tuple(sorted(items))
+        return tuple(items)
 
 
 # end::TOMBOLA_ABC[]

13-protocol-abc/tombola_runner.py

@@ -1,4 +1,5 @@
-# tag::TOMBOLA_RUNNER[]
+#!/usr/bin/env python3
+
 import doctest
 
 from tombola import Tombola
@@ -13,8 +14,7 @@
 def main(argv):
     verbose = '-v' in argv
     real_subclasses = Tombola.__subclasses__()  # <2>
-    virtual_subclasses = list(Tombola._abc_registry)  # <3>
-
+    virtual_subclasses = [tombolist.TomboList]  # <3>
     for cls in real_subclasses + virtual_subclasses:  # <4>
         test(cls, verbose)
 
@@ -33,4 +33,3 @@ def test(cls, verbose=False):
 if __name__ == '__main__':
     import sys
     main(sys.argv)
-# end::TOMBOLA_RUNNER[]

13-protocol-abc/tombola_tests.rst

@@ -11,8 +11,8 @@ Create and load instance from iterable::
     >>> globe = ConcreteTombola(balls)
     >>> globe.loaded()
     True
-    >>> globe.inspect()
-    (0, 1, 2)
+    >>> sorted(globe.inspect())
+    [0, 1, 2]
 
 
 Pick and collect balls::

13-protocol-abc/tombolist.py

@@ -18,6 +18,6 @@ def loaded(self):
         return bool(self)  # <6>
 
     def inspect(self):
-        return tuple(sorted(self))
+        return tuple(self)
 
 # Tombola.register(TomboList)  # <7>

15-more-types/cafeteria/contravariant.py

@@ -38,8 +38,7 @@ def deploy(trash_can: TrashCan[Biodegradable]):
 # tag::DEPLOY_NOT_VALID[]
 compost_can: TrashCan[Compostable] = TrashCan()
 deploy(compost_can)
-# end::DEPLOY_NOT_VALID[]
-
-## Argument 1 to "deploy" has
+## mypy: Argument 1 to "deploy" has
 ## incompatible type "TrashCan[Compostable]"
 ##          expected "TrashCan[Biodegradable]"
+# end::DEPLOY_NOT_VALID[]

15-more-types/cafeteria/covariant.py

@@ -38,11 +38,12 @@ def install(dispenser: BeverageDispenser[Juice]) -> None:  # <3>
 install(orange_juice_dispenser)
 # end::INSTALL_JUICE_DISPENSERS[]
 
-################################################ not a juice dispenser
+################################################ more general dispenser
 
+# tag::INSTALL_BEVERAGE_DISPENSER[]
 beverage_dispenser = BeverageDispenser(Beverage())
-
-## Argument 1 to "install" has
+install(beverage_dispenser)
+## mypy: Argument 1 to "install" has
 ## incompatible type "BeverageDispenser[Beverage]"
 ##          expected "BeverageDispenser[Juice]"
-install(beverage_dispenser)
+# end::INSTALL_BEVERAGE_DISPENSER[]

15-more-types/cafeteria/invariant.py

@@ -37,7 +37,7 @@ def install(dispenser: BeverageDispenser[Juice]) -> None:  # <4>
 # tag::INSTALL_BEVERAGE_DISPENSER[]
 beverage_dispenser = BeverageDispenser(Beverage())
 install(beverage_dispenser)
-## Argument 1 to "install" has
+## mypy: Argument 1 to "install" has
 ## incompatible type "BeverageDispenser[Beverage]"
 ##          expected "BeverageDispenser[Juice]"
 # end::INSTALL_BEVERAGE_DISPENSER[]
@@ -48,7 +48,7 @@ def install(dispenser: BeverageDispenser[Juice]) -> None:  # <4>
 # tag::INSTALL_ORANGE_JUICE_DISPENSER[]
 orange_juice_dispenser = BeverageDispenser(OrangeJuice())
 install(orange_juice_dispenser)
-# end::INSTALL_ORANGE_JUICE_DISPENSER[]
-## Argument 1 to "install" has
+## mypy: Argument 1 to "install" has
 ## incompatible type "BeverageDispenser[OrangeJuice]"
 ##          expected "BeverageDispenser[Juice]"
+# end::INSTALL_ORANGE_JUICE_DISPENSER[]

15-more-types/cast/empty.py

@@ -0,0 +1,2 @@
+# Mypy 0.812 can't spot this inevitable runtime IndexError
+print([][0])

15-more-types/cast/find.py

@@ -0,0 +1,23 @@
+# tag::CAST[]
+from typing import cast
+
+def find_first_str(a: list[object]) -> str:
+    index = next(i for i, x in enumerate(a) if isinstance(x, str))
+    # We only get here if there's at least one string in a
+    return cast(str, a[index])
+# end::CAST[]
+
+
+from typing import TYPE_CHECKING
+
+l1 = [10, 20, 'thirty', 40]
+if TYPE_CHECKING:
+    reveal_type(l1)
+
+print(find_first_str(l1))
+
+l2 = [0, ()]
+try:
+    find_first_str(l2)
+except StopIteration as e:
+    print(repr(e))