Data type for Float column should be float, not Decimal #178
Description
Related to: #131
About
#132 fixed #131, a bug that sqlalchemy.Numeric was treated as float, not decimal.Decimal.
But it may introduce a new bug, that sqlalchemy.Float is also treated as decimal.Decimal, not float.
To reproduce
Assigning a float value to sqlalchemy.Float is enough to reproduce this bug.
Below is a sample code to reproduce:
from decimal import Decimal
from sqlalchemy import Column, Float, Numeric, Integer
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class Numbers(Base):
__tablename__ = "numbers"
id_ = Column(Integer, primary_key=True)
c_numeric = Column(Numeric, nullable=False)
c_numeric_as_decimal = Column(Numeric(asdecimal=True), nullable=False)
c_numeric_as_float = Column(Numeric(asdecimal=False), nullable=False)
c_float = Column(Float, nullable=False)
def in_float() -> None:
number = 1.0
numbers = Numbers(c_numeric=number, c_numeric_as_decimal=number, c_numeric_as_float=number, c_float=number)
print(type(numbers.c_numeric), type(numbers.c_numeric_as_decimal), type(numbers.c_numeric_as_float), type(numbers.c_float))
def in_decimal() -> None:
number = Decimal(1.0)
numbers = Numbers(c_numeric=number, c_numeric_as_decimal=number, c_numeric_as_float=number, c_float=number)
print(type(numbers.c_numeric), type(numbers.c_numeric_as_decimal), type(numbers.c_numeric_as_float), type(numbers.c_float))
in_float()
in_decimal()$ mypy foo.py
foo.py:21: error: Incompatible type for "c_numeric" of "Numbers" (got "float", expected "Decimal")
foo.py:21: error: Incompatible type for "c_numeric_as_decimal" of "Numbers" (got "float", expected "Decimal")
foo.py:21: error: Incompatible type for "c_numeric_as_float" of "Numbers" (got "float", expected "Decimal")
foo.py:21: error: Incompatible type for "c_float" of "Numbers" (got "float", expected "Decimal")
Found 4 errors in 1 file (checked 1 source file)
Expected result
$ mypy foo.py
foo.py:21: error: Incompatible type for "c_numeric" of "Numbers" (got "float", expected "Decimal")
foo.py:21: error: Incompatible type for "c_numeric_as_decimal" of "Numbers" (got "float", expected "Decimal")
foo.py:26: error: Incompatible type for "c_numeric_as_float" of "Numbers" (got "Decimal", expected "float") # this one
foo.py:26: error: Incompatible type for "c_float" of "Numbers" (got "Decimal", expected "float") # this one
Found 4 errors in 1 file (checked 1 source file)
Environment
$ (cd sqlalchemy-stubs && git rev-parse HEAD)
55470ceab8149db983411d5c094c9fe16343c58b
$ python -c "import sqlalchemy; print(sqlalchemy.__version__)"
1.3.20
$ python -V
Python 3.8.2
$ mypy -V
mypy 0.790