FazBrowse GitHub Viewer | Trending |
URL:
| Home
Tools: [Download Repo ZIP]   [Original HTTPS Page]

gh-96130: Rephrase use of "typecheck" verb for clarity by hauntsaninja · Pull Request #98144 · python/cpython · GitHub

/ cpython Public

gh-96130: Rephrase use of "typecheck" verb for clarity #98144

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
JelleZijlstra merged 1 commit into from
Oct 12, 2022
Conversation 3 Commits 1 Checks 0 Files changed
Merged

gh-96130: Rephrase use of "typecheck" verb for clarity #98144

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension .rst  (1) All 1 file type selected
Viewed files
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Unified
Split
Hide whitespace
Diff view
Unified
Split
Hide whitespace
20 changes: 10 additions & 10 deletions Doc/library/typing.rst
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -105,7 +105,7 @@ A type alias is defined by assigning the type to the alias. In this example,
def scale(scalar: float, vector: Vector) -> Vector:
return [scalar * num for num in vector]

# typechecks; a list of floats qualifies as a Vector.
# passes type checking; a list of floats qualifies as a Vector.
new_vector = scale(2.0, [1.0, -4.2, 5.4])

Type aliases are useful for simplifying complex type signatures. For example::
Expand Down Expand Up @@ -147,10 +147,10 @@ of the original type. This is useful in helping catch logical errors::
def get_user_name(user_id: UserId) -> str:
...

# typechecks
# passes type checking
user_a = get_user_name(UserId(42351))

# does not typecheck; an int is not a UserId
# fails type checking; an int is not a UserId
user_b = get_user_name(-1)

You may still perform all ``int`` operations on a variable of type ``UserId``,
Expand All @@ -176,7 +176,7 @@ It is invalid to create a subtype of ``Derived``::

UserId = NewType('UserId', int)

# Fails at runtime and does not typecheck
# Fails at runtime and does not pass type checking
class AdminUserId(UserId): pass

However, it is possible to create a :class:`NewType` based on a 'derived' ``NewType``::
Expand Down Expand Up @@ -463,12 +463,12 @@ value of type :data:`Any` and assign it to any variable::
s = a # OK

def foo(item: Any) -> int:
# Typechecks; 'item' could be any type,
# Passes type checking; 'item' could be any type,
# and that type might have a 'bar' method
item.bar()
...

Notice that no typechecking is performed when assigning a value of type
Notice that no type checking is performed when assigning a value of type
:data:`Any` to a more precise type. For example, the static type checker did
not report an error when assigning ``a`` to ``s`` even though ``s`` was
declared to be of type :class:`str` and receives an :class:`int` value at
Expand Down Expand Up @@ -500,20 +500,20 @@ reject almost all operations on it, and assigning it to a variable (or using
it as a return value) of a more specialized type is a type error. For example::

def hash_a(item: object) -> int:
# Fails; an object does not have a 'magic' method.
# Fails type checking; an object does not have a 'magic' method.
item.magic()
...

def hash_b(item: Any) -> int:
# Typechecks
# Passes type checking
item.magic()
...

# Typechecks, since ints and strs are subclasses of object
# Passes type checking, since ints and strs are subclasses of object
hash_a(42)
hash_a("foo")

# Typechecks, since Any is compatible with all types
# Passes type checking, since Any is compatible with all types
hash_b(42)
hash_b("foo")

Expand Down
Back | FazBrowse Home | New Git URL