pytype cannot recognize a List[TypedDict] of more than 63 elements

[qxcv]

I have a list of dicts annotated with as List[T] where T is a TypedDict. I've found that pytype complains when it has more than 63 elements. Here's a working example (pytype_fail.py):

from typing import List, TypedDict

class T(TypedDict):
    a: str

list63: List[T] = [
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
]
list64: List[T] = [
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
    {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'}, {'a': 'a'},
]

Expected pytype output: type checks pass, everything is okay.

Actual output with 2023.07.28: fails on the list64 declaration (but not the list63 declaration) with this error:

Computing dependencies
Analyzing 1 sources with 0 local dependencies
ninja: Entering directory `.pytype'
[1/1] check pytype_fail
FAILED: /.../.pytype/pyi/pytype_fail.pyi 
/.../python -m pytype.single --imports_info /.../.pytype/imports/pytype_fail.imports --module-name pytype_fail --platform linux -V 3.10 -o /.../.pytype/pyi/pytype_fail.pyi --analyze-annotated --enable-cached-property --nofail --quick /.../pytype_fail.py
File "/.../pytype_fail.py", line 16, in <module>: Type annotation for list64 does not match type of assignment [annotation-type-mismatch]
  Annotation: List[T]
  Assignment: List[Dict[str, str]]
  
  TypedDict missing keys: a

For more details, see https://google.github.io/pytype/errors.html#annotation-type-mismatch
ninja: build stopped: subcommand failed.
Leaving directory '.pytype'

[wyattscarpenter]

I've also found that it complains with a dict of TypedDicts of more than 63 elements.

[wyattscarpenter]

Ah, this is just #1545